US2968983A

US2968983A - Rotary impact perforating machine having positive punch retracting means

Info

Publication number: US2968983A
Application number: US581862A
Authority: US
Inventors: Walter F Cousino
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-05-01
Filing date: 1956-05-01
Publication date: 1961-01-24
Anticipated expiration: 1978-01-24

Description

1961 w. F. COUSINO 2,968,983

ROTARY IMPACT PERFORATING MACHINE HAVING POSITIVE PUNCH RETRACTING MEANS 2 Sheets-Sheet 1 Filed May 1, 1956 l N I EH E. fimgwww hr Q 1 um Q JNVENTOR WAL TEE f. DUI/BIND BY 7M hm WW w. F. cousmo 2,968,983 ROTARY IMPACT PERFORATING MACHINE HAVING POSITIVE PUNCH RETRACTING MEANS Jan. 24, 1961 2 Sheets-Sheet 2 Filed May 1, 1956 r l h mm MENU Mb 3 x J 1- I, mm :1 mm wmw l %m N\ w o m mm A 5 mW n 5 T F. M H E Y W m ROTARY IMPACT PERFORATING MACHINE HAV- lNG POSITIVE PUNCH RETRACTING MEANS Walter F. Cousino, 2160 Mount Vernon, Toledo, Ohio Filed May 1, 1956, Ser. No. 581,862

4 Claims. (Cl. 83-355) The present invention relates to high-speed punching or perforating machines, and more particularly to a perforating machine having a bar or the like connected to the frame for transmitting impacts from a rotating impact wheel to a reciprocating punch.

This application is a continuation-in-part of my copending application, Serial No. 273,215, filed February 25, 1952, now abandoned; a continuation in part of my copending application, Serial No. 307,479, filed September 2, 1952, now abandoned; and, a continuation-in-part of my copending application, Serial No. 374,953, filed August 18, 1953, now abandoned.

The machine of the present invention has a punch for rapidly and successively punching holes or indentations in, or pieces from, a strip of sheet material, such as for example, in motion picture film, in metal strips which are weakened by slots punched therein so they can be readily channeled and bent without buckling and used to reinforce felt and rubber guides around the edges of windows, or in decorative metal or plastic strips.

According to the present invention, the punch is mounted on the frame for reciprocation vertically toward and away from a die carried by the frame and positiveacting means is provided for imparting hammer blows to the punch including an impact wheel or flywheel having at least one impact member. The bar is connected to the frame so as to absorb forces which would tend to bend the punch and is o-perably connected to the punch to transmit hammer blows to the punch. One of the impact members is preferably a roller so as to minimize friction and damage to the parts. Means is provided for feeding a strip of material to the die to be perforated and for driving the impact wheel and the feeding means continuously in synchronism so that the strip is perforated at predetermined intervals.

Each impact member on the flywheel occupies a very small fraction of the circumference of the impact wheel or flywheel, and the impact member associated with the bar normally projects only a small fraction of an inch into the path of movement of the former impact member on the flywheel, whereby the former impact member strikes and moves into and out of the space normally occupied by the latter impact member in a few degrees of rotation of the flywheel. A fast-acting means may be provided for retracting the punch and for returning the impact member of said bar to its normal position in the path of movement of the impact member on the flywheel so that the punch moves into and out of engagement with the strip material in a few degrees of rotation of the flywheel. By minimizing the period of time in which the punch engages the strip material, it is possible to drive the feed rolls or other strip feeding means continuously at constant speed, and the material may be fed at high speeds which would be impractical with an intermittent fe d. Means, such as a stripper plate or the like, is preferably provided to facilitate high-speed removal of the punch from the strip so that high-speed operation is possible. 1

tates Patent 2,968,983 Patented Jan. 24, 1961 A fast-acting retracting means for the punch can be provided by positive-acting means similar to the positiveacting means for moving the punch toward the die. The hammer blows imparted to the punch by the impact members and the fast action of the retracting means permits extremely high speed operation. The peripheral speed of movement of the impact members on the flywheel is preferably between about 1500 and 8000 feet per minute, but higher speeds are possible.

An object of the invention is to provide a simple and inexpensive perforating or punching machine which may be operated at high speeds.

A further object of the invention is to provide a machine which minimizes the cost of perforating strip material.

Another object of the invention is to provide a machine which perforates accurately when operated at substantial speeds.

A still further object of the invention is to provide a perforating machine or the like wherein the strip material is fed continuously in synchronism with the punchimpacting means without the need for intermittent feeding mechanism to stop movement of the strip during each perforating operation.

Another object of the invention is to provide means for stopping perforation of the strip material without stopping operation of the punch-impacting means.

The above mentioned and other features and objects of this invention and the manner of attaining them are given more specific disclosure in the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

Fig. l is a side elevational view of one embodiment of the perforating machine of this invention with the driving motor broken away along line II of Fig. 2, and a portion of the frame and die mounting block broken away to show one embodiment of a resilient punch or die retracting means;

Fig. 2 is an end elevational view of the perforating machine showing the feeding rolls for the strip of stock to be perforated;

Fig. 3 is an enlarged side elevational view of one embodiment of a perforating mechanism of a machine similar to that shown in Fig 1 with adjacent parts thereto shown only in part, showing the lever means, another type of impact member on the rotating disk,

and another type of punch-retracting mechanism; theparts being shown in their positions just after the impact member of the flywheel strikes the impact-transmitting bar and before the punch has passed through the strip material;

Fig. 3a is a fragmentary view of the flywheel from the right of Fig. 3 showing the projection on the side of the impact member forming a part of the retracting means;

Fig. 4 is a front view of the perforating mechanism from the right of Fig. 3 with portions of the positive mechanical punch-retracting mechanism broken away to show its operative parts; and,

Fig. 5 is a fragmentary plan view showing a portion of a partially perforated strip of material, the perforations of which can be produced on either of the machines shown in Figs. 1 through 4.

Referring more particularly to the drawings, in which like parts are referred to by the same numerals throughout the several views, Figs. 1 and 2 show a perforating machine according to the present invention having a rigid frame including a horizontal base plate 10 and a pair of upright metal supports or standards 11 and 12 rigidly connected to said base plate. The standards are bifurcated at their upper ends to provide vertical ways for a pair of slidable rectangular bearing blocks 13 and 14 which are rigidly held in adjusted vertical positions on the frame by bolts and nuts 16 as best shown in Fig. 1. A horizontal metal shaft 20. extends through the bearing blocks 13 and 14 and is journaled therein for rotation about a horizontal axis. A flat solid circular metal disk or flywheel 21 of substantial weight is, located between the bearing blocks and is bolted to a pair of. annular metal face plates 23 and 24, said plates being keyed to and rigidly mounted on the shaft so that the. flywheel rotates in unison with the shaft.

The opposite end portions of the shaft 20 extend beyond the uprights 11 and 12 of the frame. As herein shown, an annular pulley 25 is, mounted on and keyed to one end portion of the shaft, said pulley being operably connected by an endless V-belt 26 and an. annular pulley 27 to the'horizontal' driving shaft of a reductiongeared electric motor assembly 28 or other suitable power source. The housing for the motor at 28 may be pivotally and adjustably mounted on the base plate 10 to maintain the belt 26 taut. As herein shown, the motor housing is rigidly mounted on said base plate by an adjustable bolt and nut means 29.

An annular pulley 30 is mounted on and keyed to the other end portion of the shaft 20, said pulley being operably connected by an endless V-belt 31 and an annular pulley 42 to the horizontal shaft 40 of a reduction gear assembly 32. Said assembly is rigidly mounted on the lateral horizontal bars of a platform 33 which is adjustably mounted on the uprights 11 and 12 by means of a pair of longitudinal horizontal bars 34, a pair of inclined struts 35 and 36, and bolt and nut means including four bolts 37. The ends of said bars adjacent the uprights 11 and 12 are provided with elongated slots 38 to permit adjustment of the reduction gear assembly 32 toward and away from the main frame, and the lower ends of said. struts are provided with similar slots 39. The upper ends of the struts are pivotally connected to the barsv 34 intermediate their ends as best shown in Fig. 1 so that the reduction gear assembly is rigidly held in an adjusted position on the frame when the nuts on the bolts 37 extending through the

slots

38 and 39 are tightened.

The gear assembly 32 has horizontal input and

output shafts

40 and 41 parallel to the shaft 20 and geared together for rotation in the same direction, the end of the shaft 40 being rigidly connected to the pulley 42' so as to be driven by the belt 31. A vertical sprocket 43 is rigidly mounted on the shaft 41 to support an endlesssprocket chain 44, the lower end of said chain being mounted on a similar vertical sprocket 45 located in the same vertical plane as the sprocket 43. The sprocket 45' is rigidly mounted on the end of a horizontal shaft of an externally cylindrical feed roll 51 so that said feed roll is driven through the sprockets and chains in the same direction of rotation as the shaft 41. The feed roll 51 is, therefore, driven from the flywheel 21 through the belt 31, the gear reduction unit 32, and the sprocket chain 44 and caused to rotate in the same direction as the flywheel but at a lower velocity, said feed roll and said flywheel being driven by the motor 28 and rotated about parallel axes in a counterclockwise direction as viewed in Fig. 1.

The belt 31 and chain 44 may be properly tensioned to remove slack by adjusting the positions of the bolts 37 relative to the

slots

38 and 39. Such adjustment eliminates any substantial slippage of the belt 31 on its

pulleys

30 and 42 and insures that the feed roll 51 is driven in synchronism with the flywheel 21.

An externally cylindrical feed roll or idler roll 52 of the same size as the driving roll 51 is rigidly mounted on a horizontal shaft 53 parallel to and directly below said driving roll (see also Fig. 3). The portions of the parallel feed roll shafts at the opposite ends of the feeding and clamping rolls are journaled in rigid vertical ears 56 and 57 located between the uprights 11 and 12 (see Figs. 2 and 3), the axes of rotation of said shafts being spaced apart a distance only slightly greater than the diameter of said feed rolls to provide a narrow space between said rolls of a size to receive a thin strip 55 of paper, metal, plastic or other suitable material.

As herein shown, said strip has a uniform width substantially equal to the width of the feeding and clamping rolls 51 and 52 and has a uniform thickness substantially equal to the vertical distance between said rolls. The Strip is guided through the main frame of the, per forating machine and is held in a substantially horizontal position as it passes between the feed rolls, said rolls engaging opposite faces of the strip to clamp and grip the strip whereby the idler roll 52 rotates at the same peripheral speed as the driving roll 51. As herein shown, the feed roll 51 is knurled. If desired, a suitable spring means may be provided to bias the idler roll toward the driving roll so that the machine can feed strips of. varying thicknesses.

A punch and die assembly A is rigidly mounted on the frame between the uprights 11 and 12 just below the flywheel, said assembly including upper and lower metal blocks 61 and 62 mounted on a pair of laterally aligned vertical cylindrical metal posts or pins 63 and 64 that are anchored to the base plate 10. Each of said blocks has a pair of internally cylindrical vertical holes therethrough of substantially the same diameter as the posts 63v and 64 so that they are accurately positioned by said posts. The upper block 61 has internally threaded holes. leading to said vertical holes to receive set

screws

181 and 182 for engaging said posts and rigidly holding the block 61 in adjusted vertical positions on said posts. The lower block 62 may be moved upwardly and held against the block 61 by suitable means, such for example as the wedge which is described in more detail hereafter.

As herein shown, the front portions of the

blocks

61 and 62 project on opposite sides of the feed rolls 51 and 52 to provide the ears 56 and 57 which rotatably support the

shafts

50 and 53 parallel to the shaft 20. Extending away from. said ears are replaceable upper and lower metal guide shoes 61 and 62' (see Fig. 3) located in rectangular recesses in the

blocks

61 and 62 above and below the. strip 55. Said shoes provide a horizontal guide channel for said strip extending substantially from the feed rolls to the punch and having a width only slightly greater than that of said strip so as to guide the strip from the feed rolls to the punch. Said horizontal channel has a substantial vertical height several times the thickness of the strip material to permit slight buckling of the strip due to engagement of the punch with the stripas the strip is being fed toward the punch by the feed rolls.

The channel between the feed rolls and the punch may be straight as shown in Fig. 3 or may be arched as shown for example in Fig. 16 and in my copending application Serial No. 374,953, filed August 18, 1953, now aban doned. Where the speed of the flywheel 21 is very high compared to the speed of the feed rolls 51 and 52, the buckling of the strip may not present a serious problem. However, fluid pressure feeding means of the type disclosed in said copending application may, if desired, be employed with the feed rolls to improve the accuracy of the perforating.

The disk orflywheel of the perforating machine is provided with one or more impact members for imparting a rapid series of hammer blows to the punch. A single impact member is; sufficient and is often preferred since it may be driven at a higher speed relative to the feed rolls, but it is often desirable to use two or more regularly spaced impact members to reduce centrifugal forces on the flywheel at a given rate of perforation and to facilitate balancing of the flywheel. As herein shown, theflywheel has, four wedge-shaped metal impact members 65 of substantially the same axial width as the flywheel equally spaced about the circumference of the flywheel and projecting radially outwardly a small fraction of an inch beyond the cylindrical outer surface of said flywheel. Each impact member 65 has oppositely inclined substantially flat

rectangular surfaces

92 and 94, the surface 92 having less Width than the surface 94 and less inclination relative to the line of movement of the punch at the instant the impact member strikes the punch.

In the cylindrical flywheel 21 of Figs. 1 and 2, the impact members 65 are held in rectangular notches 66 in the periphery of the flywheel by small removable metal wedges 67 bolted to the bottom of said notches. However, in the cylindrical flywheel 81 of Figs. 3 and 4, which is the same size as the flywheel 21, each impact member 65 fits in a tapered notch 76, the

inclined surfaces

92 and 94 of each impact member terminating at the edges of said notch.

A relatively light bar, plate or anvil member is preferably mounted between the flywheel or impact wheel and the upper end of the punch to transmit the hammer blows from the impact wheel to the punch and is connected to a rigid portion of the frame so that substantial bending forces are not transmitted to the thin punch. In the assembly A of Figs. 1 to 4, a metal impact-transmitting bar or lever 90 extends between the flywheel and the punch and is pivotally mounted above the block 61 on a horizontal cylindrical fulcrum or pivot pin 87 parallel to the axis of rotation of the flywheel. Said block has a pair of small integral vertical cars 85 which receive and support the opposite end portions of the pin 87.

The impact-transmitting bar 90 has an anvil portion or impact member which projects a small fraction of aninch into the path of movement of an impact member on the flywheel when the punch is in its normal upper position out of contact with the strip material. One of said members is preferably a roller so as to minimize the friction between the impact members. Where a series of impact rollers are provided on the flywheel, the impact member or anvil on the bar may be a non-rotatable element mounted on the bar or an integral projection on the bar. However, as shown in Figs. 1 to 4, the impact member on the bifurcated end of the bar 90 is an externally cylindrical roller 91 of substantially the same axial length as the flywheel mounted on a horizontal cylindrical pivot pin 93 carried by said end for rotation about an axis parallel to the axis of said flywheel. As herein shown, portions of the roller 91 are located in the vertical plane containing the axis of the flywheel and portions of said roller are in the path of movement of the rigid metal impact members 65 carried by said flywheel when the punch is in its normal retracted position out of contact with the strip 55 so that the roller engages the smooth inclined wedge surface 92 of each impact member 65 during each revolution of the flywheel. The punch moves only a short distance downwardly before the roller 91 is out of the path of movement of the impact members 65, said distance being only a small fraction of the radius of said roller.

A suitable stop means may be provided to limit the upward movement of the punch and the upward swinging movement of the impact-transmitting bar 90. As herein shown, the end of the bar remote from the impact roller 91 is internally threaded to receive an adjustable thumb screw or stop 95. A projecting stop member 96 is rigidly mounted on the block 61 for engagement with the bottom of the screw 95 to limit swinging movement of the bar 90.

The rounded downwardly projecting portion of the bar 99 directly below the impact roller has cylindrically curved lower surface which rests on the flat top horizontally surface of a thin generally rectangular vertical punch of sheet metal or the like which is mounted to slide a short distance vertically between suitable guide blocks, said blocks being rigidly held against the block 61 by bolts 103. The punch 100 of Figs. 3 and 4 and the punch100' of Figs. 1 and 2 are of substantially the same size and weight and are guided in the same manner, the former punch sliding between guide blocks 101 and 102 and the latter punch sliding between similar guide blocks 111 and 112. Each of said punches is comparatively light in weight and preferably moves vertically a distance not materially greater than three times the thickness of the strip 55 so that it has very little momentum and can be reciprocated several thousand times per minute without applying dangerously high forces against the flywheel which could cause misalignment of parts or damage the machine.

Each time an impact member 65 strikes the cylindrical roller 91, the end of the bar moves downwardly at high speed causing the punch or 100 to deform or perforate the strip 55. The punch is retracted and the strip 55 is advanced to a position for the next perforating operation in a short period of time less than that required for the next impact member 65 to reach the impact roller 91 so that said member strikes said roller to repeat the same operation, whereby the machine can be operated continuously at a high frequency of operation to cut a series of perforations at regularly spaced intervals.

The means for retracting the punch must operate at high speed to insure that the roller 91 is returned to the path of movement of the impact members and engages each impact member every time that member passes over said roller. The retracting means should be able to operate at a frequency of several thousand per minute. Both yieldable and positive acting retracting means may be employed. Where resilient springs are employed to retract the punch, it is preferable to employ rubber springs, leaf springs, flat springs or other springs which function well at high frequencies of vibration rather than coil springs, helical springs or the like.

In the machine of Figs. 1 and 2, the punch or punch holder 100 is retracted by resilient means including an arched or upwardly bent leaf spring or "flat spring 116 of thin resilient metal. The guide blocks 111 and 112 are provided with horizontally aligned holes there through to receive the spring 116, and a narrow slot 115 is provided in the center of the punch 100 of a size to receive the spring 116. The top central portion of the spring 116 pushes upwardly against the top marginal edge of the slot 115 to retract the punch after it has been pushed downwardly through the strip 55. The

slot 115 may have a vertical height only slightly greater,

than the thickness of the spring 116 so that said spring limits upward movement of the punch or may have a substantial vertical height to provide room for a guide and stop pin 117. 117 extends horizontally through the slot 115 of the punch 100' and limits the upward movement of said punch by contact with the bottom of the slot 115.

The assembly A of Figs. 1 to 4 includes cooperating die blocks and 152 having a vertical channel or opening therebetween of a size to receive the lower end portion of the punch 100 or 100'. Said die blocks are rigidly connected to the lower block 62 by suitable means including four screws or bolts 153 which extend horizontally through a fiat vertical rectangular outer plate 154- and rigidly hold said plate in position. The smooth flat horizontal upper surfaces of the die blocks 150 and 152 and the plate 154 are flush and engage the moving strip 55 to support it in a horizontal position as shown in Figs. 1 and 3.

A horizontal rectangular stripper plate 155 is rigidly mounted on the flat top surface of the vertical plate 154 by means of bolts 156, the flat bottom surface of said stripper plate engaging said top surface on opposite sides of the strip 55 as best shown in Fig. 4.. A small rectangular notch of a size to receive said strip is provided in the bottom of the stripper plate to guide the strip through the machine. The portion of the stripper plate above the die blocks 150 and 152 is spaced from said blocks a distance slightly greater than the thickness of In the machine of Figs. 1 and 2, pin

the strip 55, less than twice said thickness, and preferably less than 1 /2 times said thickness and is provided with a slot of a size to receive the lower end of the punch, whereby the stripper plate closely surrounds the punch to prevent the strip from being raised when the punch is retracted. This insures removal of the punch from the strip 55 after each punching or perforating operation even though several thousand punching operations are performed every minute.

In the assembly A, the punch-receiving opening formed by the dies 150 and 152 is substantially the same size as the lower portion of the punch so that the punch cuts a rectangular slot 180 in the strip 55 each time it enters the opening, the channel between the die blocks preferably being enlarged slightly below the upper end of said blocks to provide a space for removal of the pieces of scrap punched out of the strip.

The flat horizontal bottom faces of the die blocks 150 and 152' and the vertical plate 154 rest on the fiat horizontal upper surface of a tapered block 165 so as to be supported by said block. The block 165 is rigidly mounted on the lower block 62 by means of vertical bolts 166 and has a discharge opening 167 larger than the channel between the die blocks and vertically aligned with said channel. The

blocks

62 and 165 of the assembly A have smooth flat inclined

lower surfaces

168 and 169 located in the same plane. These surfaces are inclined the same as the smooth flat upper surface of the wedge block 170 and engage said upper surface as best shown in Fig. 3. The central portion of the wedge block is open below theopening 167 to provide an exit for the pieces punched out of the strip 55.

The Wedge block has a generally horizontal rack of gear teeth 171 formed along its lower edge and is mounted to slide horizontally in a channel 172 formed in the base plate between the

posts

63 and 64. The base plate has a pair of parallel shoulders 162 of rectangular cross. section at the bottom of the channel 172 which engage the wedge block 170 to guide and support the same as it slides horizontally as best shown in Fig. 4, the flat parallel vertical faces of the channel 172 above the shoulders 162 slidably engaging the flat parallel vertical side faces of, the wedge block to provide ways for guiding the block. I

A horizontal shaft 174 parallel to the axis of the flywheel and perpendicular to the wedge block 170 is journaled for rotation in three spaced

bearings

176, 177 and 178v which are rigidly carried by the base plate 10, the end of said shaft adjacent the bearing 178 having a handwheel, or crank 175 rigidly mounted thereon. A spur gear 173 is rigidly mounted on the shaft 174 between the

bearings

176 and 177, said gear having teeth which mesh with the teeth of the rack 171 so that the wedge block7170 may be moved in either direction horizontally by turning the crank 175..

Since. the lower block62 of the assembly A is mounted to, slide vertically on the

posts

63 and 64, substantially the entire weight of said block and the elements mounted, thereon. is supported. by the wedge block. 170. Said wedge block may be moved to a position to wedge the lower block 62. tightly against the upper block 61 as shown in Figs. 1 to 4 so that the parts of the machine are properly located for perforating. When the gear 173 is rotated clockwise to move the wedge block 170 to theright as viewed in Fig. 3, the lower. block 62 slides downwardly on the posts63 and 64 away from the upper block 61 and the strip material 55 carried by said lower block moves downwardly out of the path of movement of the reciprocating punch so that it is not perforated by the punch. The lower idler roll 52 carried by the block 62' also moves downwardly away from the driving roll 51 and out of clamping engagement with the strip 55' so that feeding of said strip is stopped substantially simultaneously with the stopping of the perforating operation. The wedge block 170 therefore provides a means for stopping and starting the perforating operation without having to counteract the momentum ofthe rotating disk or flywheel 21 or 81 so that the flywheel can be driven continuously at high speed even when the perforating is stopped temporarily.

The perforating machine of Figs. 3- and 4 is the same as the perforating machine of Figs. 1 and 2 except that the impact members 65' are mounted onthe flywheel in a different manner, the punch and the dies employed on the assembly A are replaced, and the punch retracting rechan-ism is of a diflerent type, the wedge block 170 operating in the same way in both machines toraise and lower the block 62 and the elements carried by said block. The flywheel 81 of Figs. 3 and 4 is the same size as the flywheel 21 and is mounted in the same way for operation in synchronism with the feed rolls 51 and 52. The four impact members 65 are also located in the same positions on the flywheel 81 as on the flywheel 21. However,- each impact member of the flywheel 81 fits in a tapered notch 76' having the same size and shape as said impact. member. A radial slot or slit '78 extends radially inwardly from the center of each said notch 76 toward the axis of the flywheel and a similar radial slot 79 which may be located a few inches away from each said notch extends radially inwardly toward said axis. Since the portion of the metal flywheel 81 between each pair of said radial slots can be forced a small distance away from the adjacent impact member 65, it is possible to slide each imp-act member axially into or out of its notch 76. The slot 79 near each impact member 65 may be provided with notches or recesses of suitable shape for receiving ascrew or peg which may be inserted into the slot to spread the slot and reduce the width of the adjacent notch 76, whereby the impact member 65 is tightly clamped in place. Since the notch 76 decreases in size in a radially outward direction, each impact member 65 may be tightly wedged against the bottom of said notch and held in place against centrifugal force.

In the assembly A of Figs. 3 and 4, the punch 1% and the guide blocks 111 and 112 of Figs. 1 and 2 are replaced by a similar punch 101i and similar guide blocks 101 and 102, said guide blocks being rigidly held against the upper block 61 by the four horizontal bolts 103. Said bolts also extend through and provide a rigid support for a positive-acting mechanical punch-retracting mechanism 130. As shown herein, the mechanism 130 has a pair of aligned horizontal cylindrical pins or impact members 131 and 132 mounted on opposite sides of the flywheel 81 for horizontal sliding movements parallel to the axis of said flywheel. Each of the impact members 65 has a frusto conical projection 80 extending axially beyond the side face of the flywheel 81, for engaging one of the pins 131 and 132. The projections or impact heads 81 are placed alternately on each side of the flywheel 81 and are so located that right after each successive impact of an imp-act member 65 on the roller 91, one and then the other of said pins 131 and 132 will be urged outwardly by one of said projections 80 away from the flat vertical face of the flywheel.

The projection 81B of Pig. 3 is behind the flywheel and is therefore shown in dotted lines in that figure, said projection being on the right side of the flywheel as viewed in Figs. 3a and 4. Another projection 80 on the other side of the flywheel (adapted to strike the pin 151) is shown in dot-dash lines in Fig. 4 in its position after the flywheel has rotated about from the position shown in solid lines in Fig. 4.

The positive-acting punch-retracting mechanism comprises an upright metal body or block 137 rigidly connected to the upper block 61 by the bolts 103 and having

rectangular portions

138 and 139 on opposite sides of the flywheel $1 out of the path of movement of the impact members 65 and the frusto-conical projections 80'. Said rectangular portions have aligned horizontal cylindricalbores of substantially the same diameter as the pins 131 and 132 for slidably receiving said plus. The block 137 has parallel horizontal cylindrical bores near the bottom of said rectangular portions of a size to receive and support horizontal cylindrical pivot pins 135 and 136 located in vertical planes perpendicular to the flywheel axis. A pair of upright impacttransmitting metal levers or

bars

133 and 134 of the same size and shape are pivotally mounted on. the horizontally aligned

pins

135 and 136 and engage the pins 131 and 132. The lower ends of said levers are pivotally connected to the ends of a horizontal cam bar 140 by means of

pins

141 and 142 parallel to the

pins

135 and 136 and spaced substantially the same distance apart whereby the

levers

133 and 134 are held in parallel relationship at all times. As shown in Fig. 4, the

levers

133 and 134 hold the pins 131 and 132 so that the ends thereof adjacent the flywheel 81 are spaced apart a distance not substantially greater than the axial thickness of said flywheel plus the axial height of each projection 80 whereby one of said pins on one side of the flywheel is always in the path of movement of the projections 80 located on that side of the flywheel.

The impact-transmitting cam bar 140 is constructed so as to permit downward advancing movement of the punch 10th after an impact member 65 strikes the roller 91 and to retract the punch when a projection 80 strikes one of the pins 131 and 132, the punch being retracted in response to horizontal movement of the cam bar. As herein shown, the bar is symmetrical and is provided with an upper surface including a central cam ridge 145 and a pair of recesses on opposite sides of said ridge. The cam ridge 145 is engageable with the lower surface of a horizontal cylindrical cam pin 146 which is rigidly mounted on the punch 100 in a vertical plane midway between the

pins

135 and 136 and midway between the vertical faces of the flywheel 81. The

levers

133 and 134 therefore cause the cam ridge 145 to move from a position on one side of the cam pin 146 out of the vertical path of movement of said cam pin to a similar position on the other side of the cam pin, the recesses on opposite sides of said cam ridge permitting the punch 100 and its pin 146 to move vertically through their full stroke without engaging the bar 140 when the cam ridge is in either of said positions. Each time the cam bar 140 is moved horizontally by the action of one of the projections 80, the cam ridge or projection 145 engages the pin 146, lifts the punch 100 through a distance corresponding substantially to the height of said cam ridge and the stroke of said punch, and resets one of the

levers

133 and 134 and its cooperating pin 131 and 132 for operation by the next successive projection 80 on the flywheel.

The

levers

133 and 134 and the cam bar 140 are preferably relatively light in weight so that they may be accelerated rapidly. The hammer blows of the projections 80 and the pins 131 and 132, therefore retract the lightweight punch 100 at high speed so that the punch engages the strip 55 for a minimum period of time.

The positive-acting punch-retracting mechanism 130 may be the sole means for retracting the punch 100 or may be assisted by a yieldable punch-retracting means. As shown in Fig. 3, an aperture 120 is made in the slide block 101 to provide room for a helical metal spning 121 and a hole 110' is provided in the member 61 to provide room for an L-shaped metal lever 122. The lever 122 is located in the hole 110 and has a horizontal leg that projects through a hole 123 in the punch 100 slightly larger than said leg, the inner upwardly bent leg of said lever having an end that engages the top horizontal wall of the hole 110' to serve as a fulcrum for the lever. The resilient spring 121 engages the bottom of the lever 122 and yieldably presses the lever upwardly to maintain the upright fulcrum leg of the lever against the top of the hole 110 at all times and to maintain the horizontal leg of the lever against the top of the hole 123 at all times so that the punch is biased upwardly by the spring. It is advantageous to employ the lever 122 with the spring so as to reduce the amount of movement of the springs during reciprocation of the punch. It will be understood that the lever 122 and the spring 121 are not essential to the operation of the positive-acting means and may be omitted if desired.

The lever 122 may be arranged to limit the upward movement of the punch 100 or other suitable stop means may be provided. If desired, the upward movement may be limited by engagement of the roller 91 with the cylindrical outer surface of the flywheel. Means may also be provided in the slide block 102 to limit the upward movement of the pin 146. However, as herein shown, the stop means comprises a stationary limit pin 117 which extends through a slot 147 in the punch 100.

It will be apparent that the impact heads 80 may be located at different places relative to the impact members 65 and need not be located on said impact mem bers. If desired, the heads 80 may he heads of the pegs 80' and spaced from the impact members 65 as shown in my copending application Serial No. 273,215, now abandoned, in which case both faces of each impact member 65 would be flat and flush with the flat vertical faces of the flywheel 81. With such a construction, the spring 121 could be designed to function independently of the positive-acting means 130 and to retract the punch out of the strip material before an impact head 30 struck one of the pins 131 and 132. The means 130 would insure that the punch was retracted if the spring 121 should fail but could be omitted since fast operation could be obtained with the spring alone.

In the machine in accordance with the invention, the stroke of the punch is adjusted by means of the set screws 131 and 182. The thickness of the material may also vary in this machine due to the action of the wedge 170.

The flywheel in accordance with the invention may have a diameter of about one to two feet and is rotated at speeds preferably not substantially less than 400 revolutions per minute and preferably not substantially greater than 2000 revolutions per minute although higher angular speeds are possible. The peripheral speed of the flywheel is preferably in the neighborhood at about 300 to 1500 inches per second. Since more than ten successive impact members can sometimes be employed on a single flywheel, perforating with a single punch at a rate of more than 10,000 perforating strokes per minute is conceivable with the machines of the present invention.

It is apparent that, as shown in the drawings, the total circumferential extent of all the impact members on the flywheel of the machines shown herein is no more than ten percent of the circumference of the flywheel and is less than ten percent of the circumferential travel of each impact member per revolution of the flywheel. Each impact member preferably occupies less than five percent of the circumference of the flywheel and less than five percent of the circtnnferential travel per revolution of each impact member on the flywheel, the circumferential extent of each impact member normally being no greater than about two inches. Each impact roller in any of the perforating machines shown herein has a diameter less than five percent of the circumference of the flywheel and no greater than about two inches. The impact roller preferably has a diameter in the neighborhood of about V2 to 1% inches.

In Figs. 1 to 4, the flywheels 21 and 81 are shown with a diameter of about two feet and the roller 91 has a diameter of about one-half an inch, the

surfaces

92 and 94 extending less than 3 and not substantially more than one-half an inch around the circumference of the flywheel. However, the machines are preferably designed with a flywheel having a diameter of about 15 to 20 inches and an impact roller having a diameter in the neighborhood of about one inch.

In each of the machines, the impact members are shaped so that the punch is accelerated rapidly and so that a hammer blow is imparted to the punch. Further there is a substantial area of contact at the instant the impact members strike each other and the engaging surfaces are inclined relative to the direction of movement of the impact member on the flywheel so that a substantial velocity is imparted to the punch. The circumferential path of travel (or orbit) of each impact member on the flywheel has a diameter in the neighborhood of about 1 to 2 feet, and the impact members are shaped so that the flywheel rotates no more than about 3 from the instant a first impact member on the flywheel strikes a second impact member on the impact-transmitting bar until the instant that the lowest point of said first impact member is directly above and in the vertical plane of the highest point of said second impact member.

In the machines shown, the impact member which engages an impact roller has a roller-engaging surface that is inclined substantially relative to the horizontal and is shaped so that the circumferential or orbital movement (and the movement of the central portion) of the impact member on the flywheel is not substantially more than about 0.4 inch from the instant that the flywheel impact member strikes the impact member on the bar to the instant that the lowest point on said flywheel impact member is directly above the highest point on the impact member on said bar. When the roller-engaging impact member is shaped in this manner, it is possible to impart a downward speed to the punch which is greater than half the speed of the impact members on the flywheel in their travel about the flywheel.

In the drawings for example, the radially innermost point on the roller-engaging surface 92 which moves through the space normally occupied by the impact roller 91 is spaced from the radially outermost point of the impact member 65 a distance no more than about 0.3 inch (and preferably less than about 3 times the distance that the roller 91 normally projects into the path of movement of the member 65) so that the punch mus-t move to the bottom of its stroke within a few degrees of rotation of the flywheel. The uppermost point of the roller 91 preferably projects around 0.02 to 0.1 inch into the path of movement of each impact member 65. The rotational speed of the radially outermost point of each impact member 65 is preferably about 300 to 1500 inches per second.

The hammer blow of an impact member on the flywheel accelerates the impact member on the bar very rapidly so that the impact member on the flywheel moves a circumferential distance not substantially greater than about 0.2 inch from the instant of first impact until the impact member on the bar moves out of contact with the impact member on the flywheel. The light-weight construction of the punches and the impact-transmitting bar permits rapid acceleration of the punch. The machines may be designed so that when running at normal speed with the impact members moving at speeds of around 300 to 1500 inches per second, the punch attains a downward velocity of more than 700 feet per minute and more than half the orbital speed of circumferential travel of the impact member on the flywheel while passing through the strip material. The fast-acting retracting means in each of these. machines, may be designed to impart an upward velocity to the punch before it moves,

out of the, strip which is just as high as the downward velocity.

In the machines of the invention, the impact members are shaped so that there is a substantial area of contact between the impact members at the instant of impact to absorb the hammer blow and to prevent permanent deformation of either impact member. Each non-rotatable impact member which, engages an impact roller is provided with a cylindrically or arcuately curved concave surface having an axial width of at least one inch and a uniform radius of curvature equal to the radius of the external cylindrical surface of the impact roller (which has an axial width greater than one inch). Said concave surface at the moment of impact is coaxial with the impact roller and engages the roller throughout preferably at least around 0.04 inch of its circumference and no more than 0.3 inch of its circumference. The amount of the roller circumference engaged by said concave surface is preferably not substantially less than the distance that the impact member on the flywheel projects into the path of movement of the impact member on the impacttransmitting bar.

In order to permit a fast return of the punch, the impact member engaging the impact roller preferably is provided with oppositely inclined surfaces, such for example as the

surfaces

92 and 94, so that the interference of the impact member is small. In each of the machines, the circumferential path of travel of the impact member on the flywheel has a diameter of around 1 or 2 feet,

said impact member is moving in its orbit or path at a speed of around 300 to 1500 inches per second, and the impact member on the flywheel moves into engagement with and into and out of the space normally occupied by the impact member on the bar during a period of time not substantially greater than that required for the flywheel to rotate through an angle of about 5 degrees. The impact member on the flywheel preferably moves into and out of said space while moving about 0.1 to 0.8 inch. It will be understood that the circumferential travel of the flywheel impact rollers wherever mentioned in this application refers to their travel about the flywheel axis without considering the rotation of each roller about its own axis.

In each of the machines, fast-acting means is provided for retracting the punch. The positive-acting punch-retracting means 130 of Figs. 3 and 4 is capable of moving the punch upwardly just as fast as it is moved downwardly by the impact members 65. Each impact member moves into the space normally occupied by the pin 131 or 132 positively to prevent the pin from occupying that space while moving less than 0.4 inch and less than 3 in its circumferential path and moves into and out of said path while moving about 0.1 to 0.8 inches and less than 5 in its circumferential path. The machine may be designed so that, when the impact members have a velocity of 300 to 1500 inches per second, the hammer blow of an impact member 80 causes the punch to attain an upward velocity of more than 700 feet per minute and more than half the peripheral speed of the impact member 80 before the punch moves out of the strip material.

In order to minimize the time that the punch engages the strip, the impact members 80 and the pins 131 and 132 may be so located that an impact member 80 strikes one of said pins after the punch is near the bottom of its stroke and after the impact member 65 has moved about 0.1 to 0.5 inch from its position at the instant of first impact with the roller 91. The retracting mechanism may be constructed so that the punch is moved from the bottom to the top of its stroke during movement of an impact member 65 through a distance of about 0.1 to 0.5 inch whereby the punch is returned to its normal retracted position before the impact member 65 has moved one inch from its position at the instant of impact with the roller 91.

Where the impact heads 80 are at the ends of the screws 80' as shown in my copending application Serial No. 273,215, an extremely fast return of the punch may be effected before the impact member 80 strikes one of the. pins 131 and 132 by using a rubber spring or a strong coil spring which is under considerable compression when the punch is retracted and is further compressed when the punch is moved downwardly.

The machines in accordance with the invention employ constant speed feed rollers driven continuously in synchronism with the constant speed flywheel for feeding the strip material to the die to be perforated by the punch, employs a stripper plate to facilitate high-speed removal of the punch from the strip and can be operated to provide more than 2000 perforating strokes per minute. The clearance between the top of the strip and the stripper plate may be less than 0.01 inch and even less than 0.003 inch. The feed rate of the strip material will vary considerably depending on the type of work done but is usually about 0.01 to 0.4 inch per stroke of the punch. In each of the machines, the strip is free to bend or buckle between the feed rolls and the punch during the time the punch engages the strip.

It will be understood that the stroke of the punch in each species of the invention is the stroke when the machine is operating at normal speed and While the impact members are moving at velocities of around 300 to 1500 inches per second. The stroke will be greater than the radial interference between the impact members and is usually at least 2 or 3 times the thickness of the material. The stroke is usually not more than about 0.1 inch and for very high speed operation is preferably not sub.- stantially greater than about 0.05 inch. The impact member on the bar projects about 0.02v to 0.1 inch into the path of movement of an impact member on the flywheel. The stroke of the punch may be varied by varying the initial tension on the return spring and in other ways.

It will be understood that, in accordance with the provisions of the patent statutes, variations and modifications of the specific devices disclosed herein may be made without departing from the spirit of the invention.

Having described my invention, I claim:

1. A machine having a reciprocating punch for perforating and stamping strips of sheet material comprising a frame, a punch guide and a die mounted on said frame, a light-weight reciprocating punch slidable in said guide, one end of the punch projecting beyond the punch guide, a pair of feed rolls mounted on said frame to feed said sheet material between said punch and die, a channel being formed in said frame and punch guide to conduct said sheet material from said feed rolls through said punch and die, a lever with its free end resting on the end of the punch projecting beyond the punch guide and with its other end mounted on a fulcrum pivot, a flywheel mounted on said frame with its shaft at substantially right angles to the centerline of the punch, a plurality of cams distributed about the circumference of said flywheel to strike said lever to in turn drive said punch through said sheet material, means to retract said punch, and a motor mounted on said frame to drive said flywheel and said feed rolls, said punch being provided With a pin projecting at substantially right angles therefrom in the plane of the flywheel, the means for retracting said punch comprising a cam bar with a pair of detents adapted to receive the free end of said pin and a central cam ridge between said detents, levers pivoted at each end of said cam bar in turn pivotally mounted on said frame, projecting pegs mounted about the circumference of the flywheel at alternately opposite sides thereof, and pins slidably mounted on said frame adapted to be struck by said pegs to in turn strike the other end of said levers, whereby on rotation of the flywheel one of the pegs strikes one of the slidably mounted pins to drive the adjacent lever away from the flywheel and drive the cam bar toward the flywheel, lift the punch pin onto the central cam ridge of the cam bar, retract the punch and also drive the other lever toward the flywheel to return and place it in the path of the neXt projecting peg.

2. A machine for perforating sheet material comprising a frame, a die mounted on said frame, a punch mounted for reciprocation in said frame toward and away from said die, means for feeding said sheet material between said punch and die, a disc rotatably mounted on the frame, a plurality of impact members carried by said disc adjacent its periphery, a first lever pivotally supported on said frame with one arm resting on that end of the punch remote from the die, at least a portion of said arm normally being in the path of movement of said impact members for transmitting impacts to said punch to drive the same through said sheet material, and positive-acting means to retract said punch and return the first lever into the path of movement of said impact members including projections spaced about the circumference of said disc at alternately opposite sides thereof, second lever means pivotally supported on said frame and including actuators on either side of said disc positioned for operative engagement with said projections, a connection between said actuators, and means extending from said punch for cooperation with said second lever means whereby said punch is retracted and said first lever returned to the path of movement of said impact members by engagement of either of said actuators with one of said projections.

3. A machine for perforating sheet material comprising a frame, a die mounted on said frame, a punch mounted for reciprocation in said frame towards and away from said die, means for feeding said sheet material between said punch and die, a disc rotatably mounted on the frame, a plurality of impact members carried by said disc adjacent its periphery, a first lever pivotally supported on said frame with one arm resting on that end of the punch remote from the die, at least a portion of said arm normally being in the path of movement of said impact members for transmitting impacts to said punch to drive the same through said sheet material, and a positive-acting means to retract said punch and return the first lever into the path of movement of said impact members comprising projections spaced about the circumference of said disc at alternately opposite sides thereof, second lever means including a pair of arms pivotally supported intermediate their length on said frame on either side of said disc, the upper ends of said arms being disposed for operative engagement with said projections upon rotation of said disc, a cam bar pivotally connecting the lower ends of said arms, and a pin extending from said punch for engagement with said cam bar whereby said punch is retracted and said first lever returned into the path of movement of said impact members upon operative engagement of either of said arms with one of said projections.

4. A machine for perforating sheet material comprising a frame, a die mounted on said frame, a punch mounted for reciprocation in said frame toward and away from said die, means for feeding sheet material between said punch and die, a disc rotatably mounted on the frame, a plurality of impact members carried by said disc adjacent its periphery, a first lever pivotally supported on said frame with one arm resting on that end of the punch removed from the die, at least a portion of the arm normally being in the path of movement of said impact members for transmitting impacts to said punch to drive the same through said sheet material, a pin extending from said punch, and positive-acting means to retract said punch, and return the first lever to the path of movement of said impact members including a cam bar, with a pair of detents adapted to receive the free end of said pin and a central cam ridge between said detents. levers pivoted at each end of said cam bar and in turn pivotally mounted on said frame, a plurality of projections spaced about the circumference of said disc at alternately opposite sides thereof, and pins slidably mounted on said frame adapted to be struck by said projections to in turn strike the other end of said levers, whereby on rotation of the disc one of the projections strikes one of the slidably mounted pins to drive the adjacent lever away from the disc and drive the cam bar toward the disc, lift the punch pin onto the central cam ridge of the cam bar, retract the punch and also drive the 15 other lever toward the disc to return and place it in the path of the next projection.

References Cited in the file of this patent UNITED STATES PATENTS 16 Wales May 22, 1951 Carroll Aug. 24, 1954 Taylor Aug. 28, 1956 Baker July 30, 1957 DAngelo Sept. 2, 1958 Boschi Sept. 30, 1958 Cousino Oct. 28, 1958 FOREIGN PATENTS Great Britain Oct. 1, 1903 Sweden May 15, 1932 Great Britain May 16, 1935