US2751984A

US2751984A - Punch press

Info

Publication number: US2751984A
Authority: US
Inventors: George H Kuhl
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-02-27
Filing date: 1955-07-21
Publication date: 1956-06-26
Anticipated expiration: 1973-06-26

Description

G. H. KUHL PUNCH PRESS June 26, 1956 6 Sheets-Sheet 1 Filed July 21, 1955 June 26, 1956 G. H. KUHL 2,751,984

PUNCH PRESS Filed July 21, 1955 6 Sheets-Sheet 2 '2 jg /0Z 60f6 Z4 w G. H. KUHL June 26, 1956 PUNCH PRESS Filed July 21, 1955 6 Sheets-Sheet 3 Q NN eor ge ifjflfid J 1 7w, wk

June 26, 1956 Filed July 21, 1955 G. H. KUHL PUNCH PRESS fi JJ 5 J a/ 35 i a 45 6 Sheets-Sheet 4 G. H. KUHL PUNCH PRESS June 26, 1956 6 Sheets-Sheet 5 Filed July 21, 1955 G. H. KUHL PUNCH PRESS June 26, 1956 6 Sheets-Sheet 6 QQ MN Mi Mi m%\ 3 mQ k5 Filed July 21, l

PUNCH PRESS George H. Kuhl, Glen Ellyn, Ill.

Original application February 27, 1951, Serial No. 212,975. Divided and this application July 21, 1955, Serial No. 523,447

Claims. (Cl. 164-90) This invention relates to a punch press.

This application is a division of my co-pending application filed February 27, 1951, as Serial Number 212,975.

It is the general object of this invention to produce a new and improved punch press.

Another object of the invention is to produce a dual punch press which includes a ram carrying two male die parts and mounted for reciprocation in a horizontal plane, and two female die parts each cooperable with one of the male die parts so that two punching operations can be accomplished in each stroke of the press.

It is a more specific object of the invention to produce a dual punch press of the type described in the preceding paragraph which includes means for accurately adjusting each male die part relative to the other parts of the press in order to secure perfect alignment of the dies.

It is a further object of this invention to produce in a single apparatus a self-feeding punch press which may operate not only on one but two die sets simultaneously, each die producing either a similar or a dissimilar part and capable of operating at higher rates of speed and productivity by reason of improved distribution and proportion of moving and stationary masses of the press.

It is another object of the invention to produce a selffeeding punch press which puts to use the return stroke of the ram and thus to increase the productivity of punch presses without a corresponding increase in cost or size.

Other and further objects of the invention will be apparent from the following description and drawings, in which:

Fig. l is a side elevation of a dual punch press embodying the invention;

Fig. 2 is an end view of the upper portion of Fig. 1;

Fig. 3 is a top plan view of the apparatus shown in Fig. 1;

Fig. 4 is a vertical section along line 44 of Fig. 3;

Fig. 5 is a side elevation of the upper portion of Fig. 1 showing the opposite side of the press;

Fig. 6 is a vertical section along line 66 of Fig. 5;

Fig. 7 is a vertical section along line 77 of Fig. 3; and

Fig. 8 is a horizontal section along line 8-8 of Fig. 7.

While this invention is susceptible of embodiment in many difierent forms, there is shown in the drawings and will herein be described in detail one specific embodiment, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.

For the purpose of exemplary disclosure the feed means of this invention is shown as used in conjunction with a dual punch press. As s'hownin the drawings the press includes a frame A supporting the press B, drive means C for driving the press and the feed means D for feeding the work piece to the press.

The frame A includes rigid legs 10 adapted to support the apparatus, the legs preferably being angle irons welded -nitecl States Patent 0 or otherwisesecured together to provide a sturdy'mounting. The press B is supported on the top of the frame and includes a pair of

bolster plates

20 and 21 secured to the frame A at spaced positions and upstanding vertically therefrom in parallel relationship to each other. Extending between and secured to each of the bolster plates are four tie rods 2225 which provide the mounting means for the movable ram of the press. The ends of the tie rods are securely fastened to the bolster plates by the bolts shown. Four bearings 26-29 are provided for carrying the rams, each of the bearings being slidably mounted upon a different one of the rods.

It will be noted that the press reciprocates horizontally. This fact, together with the low center of gravity of the apparatus, increases the stability of the press and permits high speed operation.

As best shown in Figs. 4 and 5, the bearings are integrally secured to an annular collar member 30 forming a part of theram and which is provided with an internal recess 31. Secured in the recess as by the screw devices 32 is an externally threaded annular sleeve 33 which extends both ways from the recess 31 and parallel with the tie rods. The sleeve 33 is provided with an integral flange extending radially outwardly therefrom and provided with an internal channel 34 located in the recess 31 and receives the screw devices 32 previously described.

As previously stated, the particular embodiment of the invention chosen for illustration is shown as used with a dual punch press, that is a punch press which has similar parts on each side and is adapted to perform a punching operation upon each half stroke as it is reciprocated. Thus the parts of the press to the left and to the right of the recess 31 (as seen in Fig. 4) are similar. In order to avoid unnecessary repetitions only the die part on one side of the recess 31 will be described in detail, it being understood that the description applies to the die parts on the other side of the flange to which similar reference numerals carrying the letter a have been given.

A punch holder 40 is provided with an annular restricted portion 41 received within the sleeve 33 and with an outwardly extending annular portion 42 provided with external threads 43 which lie in the same plane as the threads 35 of the sleeve. The sleeves 43, however, are turned oppositely to the threads 35, for example the threads 43 may be right-hand threads while the threads 35 may be left-hand threads. A collar member 45 is provided with internal threads which engage both of the

threads

43 and 35 so that rotation of the collar member 45 serves to move the punch holder 40 inwardly and outwardly with respect to the sleeve 33. The outer face 46 of the punch holder 40 is concave in shape and preferably is shaped as a section of a sphere. Coincid-ing with the concave face 46 is a convexly spherical shaped member 47 secured to the male die plate 48.

A centrally located lug 49 is secured to the die plate 48 and received in a recess 50 in the punch holder 40. As will be noted from the drawings, the recess 50 is larger than the lug 49 so that the die plate 48 may be shifted slightly accurately to position it parallel to the bolster plates. This adjustment may be utilized to con-- pensate for manufacturing inaccuracies and its provision minimizes precision operations in the building of the press which would otherwise be necessary if the adjustment were not provided as it is necessary that the surfaces of the ram be perfectly parallel to the bolster plates. The loose fit between the lug and recess permits such alignment and a plurality of screws 51 are provided in the punch holder 40 and to clamp the male die part of the ram in properly aligned position. Preferably three such screws 51 are provided equally spaced about the boss. Secured to the die plate 45 is a die carrying plate 52 which carries the

male dies

53 and 54.

The particular press illustrated has been set up to along in the same manner as the plugs.

carry male dies for forming'washers from a continuous strip of material. Thus the die 53 serves to cut a circular hole in the material while the die 54 makes a second circular cut having a larger diameter than the first cut to form the annular washer. Scrap material is cut from the strip by cutter blades 55 and 55a each fixed to the bottom of each of the male die parts'and adapted to cut the strip against a recess formed in the opposing face of the female part of the die.

A pair of studs '56 and 56a is fixed each of the bolster plates and extend toward the ram parallel to the tie rods. 'A pair of sleeves 57 and 57a is fixed to each of the male die parts and slide on the studs in order to serve as guides for the ram during its reciprocation. It will be noted that the studs and

sleeves

56 and 57 are in vertical alignment along one side of the male die part 45 while the studs and sleeves 56a and 57a are in vertical alignment along theopposite side of the male die part 13a. Q

To the right of the male die plate is a female die plate 60 provided with

suitable openings

61 and 62 matching the male die parts. The female die plate 611 is sup ported against

spacer plates

63 and 64, the latter being secured to the bolster plate 2%. Each of the spacer plates is provided with holes extending therethrough matching the

holes

61 and 62 to provide the elongated passages shown which open into an annular recess 65 provided in the bolster plate. a

Between the male and female die parts there is provided a stripper plate 66 also provided with openings matching the openings 51 and 62 and spaced from the female plate to define a passage 67 through which the strip of material constituting the work piece is fed.

As the die is reciprocated and the work piece is fed into positions in line with the dies, the first die 53 cuts a circular opening in the strip each time the die is reciprocated. The circular plugs which are cut out by the die 53 stack up in the passage 61 and are moved therealong as the work progresses and finally drop into the annular recess 65. Similarly, the male die. part 54 completes the cutting operation to form the washer; the washers stacking up in the openings 52 and moving there- It is preferred that the male die part be provided with a projecting boss :13 properly to align the work piece with the cutting edges of that die in order to insure ,that the washers be accurately formed.

A pair of chutes 7t) and 79a communicate with the recesses 65 and 65a respectively to guide the washers as they fall from the recesses into a pair of containers 71 and 71a located at the bottom portion of the frame (Fl l). I prefer to provide two such containers inasmuch as the die parts on either side of the ram may not be similar in nature; thus for example one die part may be cutting washers having a 1 inch diameter and the other washers having a 1%. inch diameter. The

provision of two containers, one communicating with each of the recesses in the bolsters permits the segregation at the machine of differently formed parts. If desired, a

separate chute may connect with the opening 61 to separate ma pings from the washers.

Scrap material from the press continues its downward movement in the passage 67 until it strikes an inclined plate '72 supported on

brackets

73 and 74 secured to the frame, which plate directs the scrap material into a container pan (not shown) which may be placed in the lower part of the frame.

The drive means C include a motor 815 connected by means of a V belt Site a rotatably mounted pulley 82.

A pair of V belts 8S connect the pulley with a rotatably mountedfiywheel S4. The flywheel carries a crank 85 on either side thereof to each of which is secured a pitman $6. The two pitmans so provided are-each connected to opposite sides of the die,'that is to the annular collar 30 which is carried by the slides.

The flywheel 84 is fixed toa rotatably mounted shaft 87 supported at both ends in the frame and to which is fixed a gear 88 meshing with a second gear 89. The ratio of the mass of the flywheel to the mass of the male die carrying parts is high to provide sufiicient inertia for the press to perform a punching operation on each stroke. Also the high mass ratio contributes to the stability of the press. The gear 89 is fixed to a shaft 90 which carries at its outer end (Fig. 3) a pair of meshing bevel gears 91 one of which is secured to a drive shaft 92. The drive shaft )2 serves to operate the feed means D which in turn serves to advance the work piece intermittently to the die as the latter is reciprocated.

Inasmuch as the press illustrated in the drawings is a dual press two feed means are provided, one for each press. Hills the feed means are similarly constructed (and similar parts will be given similar reference numerals with the letter :1 added) each may be adjusted individually so as to feed at different rates. Thus if the press is performing two distinct operations, one on each die, feed means may be individually adjusted to feed the work piece at the proper rate in order to accommodatethe operations of each press. a

When used with a dual press, the work piece which is in the formof strips of material 101 and a, is fed from an overhead source which may be large rolls over which the material is passed. As the strips enter the press each is passed over a guide roller 101 rotatably mounted in a fitting 102 secured to the top of the feed means. A friction device 103 is provided to produce the proper tension on the work piece, the friction device including a shoe 104 fixed to the fitting 102 and a second shoe 1% slidably mounted on bolts 196 and urged against the first shoe by means of a spring 107. The'degree of friction may, of course, be adjusted by adjusting the screws 106. V V

Adjustably secured to thetop of the bolsters 20 and 21 is a mounting frame for the feed means including two spaced upright parallel plates and 111 secured at their bottoms to

base plates

112 and 113. Secured to and extending horizontally between the base plates is V a first clamping plate 114.. A second clamping plate is vertically spaced beneath the first clamping plate and secured thereto by means of bolts 116. A pair of spaced parallel horizontal shafts 117 and 118 are secured to the bolster plate and serve as the mounting means for the feed mechanism. As will be noted from an inspection of Figs. 4 and 6, the

base plates

112 and 113 are positioned above the shafts 117, 118 while the clamping plate 115 is positioned beneath the shafts. Each of the base plates and the clamping plates is provided with substantially herni-cylirrdrical grooves more accurately to fit the outer surfaces of the shafts 117 and 118 and thus the entire mounting means may he slid along the shafts 117 and 118 and clamped thereto at any desired point. Thus adjustment can be made for various thicknesses of the work piece and for various working strokes of the press. Furthermore, the adjustment of the feed units makes it possible to align the entrance of the strip into the feed means exactly opposite the exit-of the strip therefrom and perfectly aligned with the dies of the press to enable a large variety of die sets to be used. in the press. Referring now to Figs. 7 and 8,, it will be noted that the side plate 110.is provided with a rectangular cut-out portion 120 in which there is slidably mounted a block 121 which rotatably carries one end of a shaft 122 on which there is fixed a feed roller 123. A similarly con-' structed block is slidably mounted in the plate 111 and carries the other end of shaft '122. Fixed adjacent the right-hand end (as'seen in thosefigures) of the plates. 11%} and 111 is a second rotatably mounted shaft 125 to which 'is fixed a second feed roller 1'26. The roller 126 is, as clearly shown in the drawing, mounted .in parallel to the roller 123 and forms therewith a nip 127 through which the work strip 190 may be led.

Each of the

feed rollers

123 and 126 is driven fiom the drive means of the machine. As best seen in Figs. 3 and 6, the drive shaft 92 is provided with two pairs of bevel gears 135) and 130a, one of which carries a sprocket 131 over which a chain 132 is passed. The chain engages a second sprocket 133 secured to one end of the shaft 125 for driving the same.

Intermediate sprockets

134 and 135 are provided to take up the slack as the feed means may be adjusted inwardly and outwardly as previously described. Mounted on the shaft 125 adjacent the feed roll 126 is a spur gear 140 which meshes with a second spur gear 141 fixed on the shaft 122. Thus as the press is operated both of the feed rolls are positively driven.

It will be clear from the foregoing description that if the two feed rolls are pressed together to close the nip between them the strip of material 100 would be constantly fed to the press. This, of course, is not the object to be achieved in the particular type of press shown inasmuch as the press requires that the material be fed intermittently, that is, be advanced as the die parts are moved away from each other to present a fresh portion of the strip and held stationary as the die parts are brought together to perform their punching operation. Means are provided for alternately opening and closing the nip between the rolls, so that when the nip is closed the material is firmly grasped by the rolls and fed downwardly to the press. As the nip is opened both rolls lose their frictional grasp of the material and hence the frictional device holds the strip stationary against advancement until the nip is again closed.

To effect the alternate opening and closing of the nip,

the shaft 122 rotatably carries a cam 149 which cam may be fixed thereto by a plurality of set screws 150. The shaft is rotated in synchronism with operation of the press by the drive means C. A cam follower 151 rides upon the cam and is mounted in a lever arm 152 which is fixed to a shaft 153 rotatably mounted in the plates 110, 111, by a split clamp formed in the end of the lever arm through which clamp a lock screw 154 extends. As best shown in Fig. 8, the shaft 153 extends through the rectangular cut-out portion 120 in the side plate 119 and is provided with a flattened portion 155 located in a cut-out portion 156 of the block 121 and bearing against a flat face 157 thereof. A compression spring 153 has one end located in a recessed portion 159 at the end of the plate 116 while its other end bears against the adjacent face of the slidable block 121 to urge the block constantly in a direction closing the nip between the feed rolls. The force with which the spring biases the nip toward closed position may be adjusted in the usual manner by means of the screw device 160. The previously described adjustment of the lever arm relative to the shaft 153 afforded by the split clamp and lock screw 154 is provided to take advantage of the most rapid rise of the edge of the flattened surface 155 against the face 157 whenever a change is made from one thickness of stock to another.

from the foregoing it can be seen that as the shaft 153 is intermittently oscillated one edge of the flattened portion 155 thereof is brought against the face 157 of the block to shift the block laterally against the spring. inasmuch as the feed roller 123 is mounted in the block, such shifting movement of the block serves to open the nip between the rolls.

It will be noted that the cam follower 151 is mounted on the end of a bolt 162 which is threadable on the free end of the lever arm 152. A lock nut 163 is provided to lock the cam follower at any position to which it may be moved by adjustment of the bolt 162. By so adjusting the cam follower it is clear that the period of dwell of the rolls in the open nip or closed nip position may be regulated. Inasmuch as the strip is fed toward the die parts only when the nip is closed such adjustment permits regulation of the amount of material fed during each cycle of the die. Thus if the nip remains closed for a greater proportion of the cycle a longer length of material is fed than otherwise.

The timing of the opening and closing of the nip may be adjusted relative to the reciprocation of the die parts rotating the cam upon its shaft. By loosening the set screws 15%) the cam may be rotated in either direction relative to its shaft and fixed in any desired position. Thus there is provided a simple means of timing the feed of the work strip relative to the closing of the die parts. If the operator finds that the strip is in motion at the time the die parts are closed the press may be stopped and the cam 14-9 adjusted so as to open the nips slightly sooner in the cycle of the die. Again if the length of the strip to be fed during each cycle of the die is great the cam can be adjusted on its shaft so as to feed the strip during substantially the entire cycle, the nip opening just prior or simultaneously with the contact of the male die part therewith.

In the particular embodiment of the feed means chosen for illustrating the invention, manual means are provided for opening the nip between the feed rolls at any time in the cycle of the press, which means serves to maintain the nip open until manually closed. To this end a shaft 179 is rotatably mounted in the plate 111 (Figs. 6 and 7) to which is secured a handle 171 for rotating the shaft. The inner end of the shaft carries an eccentric pin 172 which bears against the bottom face of the lever arm 152. Rotation of the handle in a clockwise direction (as viewed in Fig. 7) serves to lift the lever arm and hence to open the nip between the rolls. The nip will remain open until the direction of rotation of the handle is reversed permitting the cam 149 to resume control of the nip position.

I claim:

1. A punch press comprising a base, a pair of spaced parallel bolster plates vertically upstanding from the base, a plurality of parallel tie rods extending horizontally between and secured to the bolster plates, a bearing mounted on each tie rod, a flywheel mounted on a shaft rotatably supported at each end in the base, pitmans connecting the flywheel to the bearings for reciprocating the same in a horizontal plane with rotation of the flywheel, a ram secured to the bearings, an annular sleeve integrally secured to the ram and having external threads at one end thereof, a punch holder having external threads turned opposite to the threads on the sleeve, a ring engaging the threads on the punch holder and sleeve and rotatable to shift the punch holder relative to the sleeve, said punch holder being provided with a concave outer face having a central opening therein, a male die part having a convex face coinciding with the concave face of the punch holder and a central lug having a loose fit in said opening, means for securing the lug in the opening to secure the male die part in adjusted position on the punch holder, a female die part cooperable with the male die part and carried on the base, and means for rotating the flywheel.

2. A punch press comprising a base, a pair of spaced parallel bolster plates vertically upstanding from the base, a plurality of parallel tie rods extending horizontally between and secured to the bolster plate, a bearing mounted on each tie rod, a flywheel mounted on a shaft rotatably supported at each end in the base, pitmans connecting the flywheel to the bearings for reciprocating the same in a horizontal plane with rotation of the flywheel, a ram secured to the bearings, an annular sleeve integrally secured to the ram and having external threads at one end thereof, a punch holder having external threads turned opposite to the threads on the sleeve, a ring engaging the threads on the punch holder and sleeve and rotatable to shift the bOSs relative to the sleeve, said punch 7 holder being presided with a concave outer face having a; central opening therein, a male die part having a convex face coinciding with the concave face of the punch holder and a central lug having a loose fit in said opening, means for secaring the lug in the opening to secure the male die part in adjusted position on the punch holder, 21 female die part cooperable with the male die part and carried on the base, a plurality of plates spacing the female die part from the frame, each of said plates havinga hole aligned with the female die part, a chute carried by the base and connected to said holes whereby material punched by the male die part is fed into said chute, and, means carried by the base for rotating the flywheel.

3. A punch press comprising a base, a pair of spaced parallel bolster plates vertically upstanding from the base, a plurality o'f parallel tie rods extending horizontally between and secured to the bolster plates, a bearing mounted on each tie rod, a flywheel mounted on a shaft rotatably supported at each end in the base, pitmans connecting the flywheel to the bearings for'reciprocating the same in a horizontal plane with rotation of the flywheel, a ram secured to the bearings, an annular sleeve integrally secured to the ram and having external threads at one end thereof, a punch holder'having external threads turned opposite to the threads on the sleeve, a ring engaging the threads on the punch holder and sleeve and rotatable to shift the punch holder relative to the sleeve, said punch -l'iC-l-L6I being provided with a concave outer face having a central opening therein, a male die part having a convex face coinciding with the concave face of the punch holder and a central lug having a loose fit in said opening, means for securing the lug in the opening to secure the male die part in adjusted position on the punch holder, 21 female die part cooperable with the male die part and carried on the base, a plurality of plates spacing the female die part from the frame, each of said plates having a hole aligned with the female die part, a recess in the outer face of one of the bolster plates communicating with said hole, means on the base for supporting a container, a chute opening at one end to said recess and at the other end to the container whereby material punched by the male die part is fed into said chute, and means carried by the base for rotating the flywheel.

4. A dual punch press comprising a base, a pair of spaced parallel bolster plates vertically upstanding from the base, a plurality of parallel tie rods extending hori- V zontally between and secured to the bolster plates, a caring mounted on each tie rod, a flywheel mounted on a shaft rotatably supported at each end in the base, pitmans connecting the flywheel to the bearings for reciprd eating the same in a horizotal plane with rotation of the flywheel, a ram secured to the bearings, an annular sleeve integrally secured to the ram and having external threads at each end thereof, a punch holder at each end of the sleeve, each punch holder having external threads turned opposite to the threads on the adjacent ends of the sleeve, a ring engaging the threads on one punch holder and on the adjacent end of the sleeve and rotatable to shift the punch holder toward and away from the sleeve, a second ring engaging the threads on the other punch holder and the threads of the sleeve adjacent thereto, said second sleeve being rotatable to move the last mentioned'punch holder toward and away from the sleeve, each of said punch holders being provided with a spherically concave outer face having a central opening therein, a pair of male die parts each having a convex face coinciding with the concave face of one of the punch holders and a central lug adapted to have a loose fit in each of said openings whereby each male die part may be shifted relative to a punch holder, means for securing each male die part ed on each tie rod, meansfor reciprocating the bearings on the tie rods, .a ram secured to the bearings, an annular sleeve integrally secured to the ram and having external threads atone end thereof, a punch holder having external threads turned opposite to the threads on the sleeve, a ring engaging the threads on the boss and sleeve and rotatable to shift the punch holder relative to the sleeve,

said punch holder beingprovided with a concave outer face having a central opening therein, a male die part having a convex face coinciding with the concave face of the punch holder and a central lug having a loose fit in said opening, means for securing the lug in the opening to secure the male die part in adjusted position on the punch holder, and a female die part cooperable with the male die part and carried on the base.

References Cited in the file of this patent UNITED STATES PATENTS 467,908 Altman Feb. 2, 1892 1,697,817 Kuhn Jan, 1, 1929 2,148,855 Cannon Feb. 28, 1939, 2,453,875 7 Terhune Nov. 16, 1948