US 3031905 A
Description (OCR text may contain errors)
y 1962 D. B. PHILLIPS ETAL 3,031,905
CUTTING DEVICE WITH RETAINER FOR CUT PRODUCTS IN THE TOOL. THEREOF AND SUCTION MEANS FOR STRIPPING SAID PRODUCT FROM RETAINER Filed June 20. 1957 2 Sheets-Sheet 1 INVENTOR. DAN/ 4 B. P/l/LL/P;
y 1952 D. B. PHILLIPS ETAL CUTTING DEVICE WITH RETAINER FOR CUT PRODUCTS TOOL THEREOF AND SUCTION MEANS FOR STRIPPI SAID PRODUCT FROM RETAINER Filed June 20, 195'? 2 Sheets-Sheet 2 INVENTOR. Dmv/ B PHIL L P5 650 E M MflPT/A/ BY 3, 1, CUTTING DEVICE WITH RETAINER FQR CUT This invention relates to a method and device for stripping of cutouts from blanks in the operation of hole punching. 1
In connection with hole punching machines of the rotarytype an important and vexing problem is that the cutouts from the blank spring back from the female die into the way of other-blanks and obstruct the operation ;of cutting-the next successive blank, therefore requiring the stopping of the machine in order to clear out or free the cutouts from between the rollers.
The primary object of the invention is to provide, in connection with'rotary hole punching machines,- particularly of the type Where the respective male and female dies are on the peripheries of opposite generally cylindrical rollers between which blanks are fed for the purpose of punching holes or slots, in blank sheets in prearranged relation, of a method whereby the periphery or ends of the cutouts are held' in the female die and are prevented from springing out of the same, so as to be pushed inwardly through the female die and thus out of the cutting area of the machine.
Weare aware that some changes may be made inthe general arrangements andcombinations of the several device and parts, as well asin the details of the construction thereof without departing from the scope of the present invention as setforth in the following specification, and, as defined in the following claims; hence we do not limit our invention to the exact arrangements.
and combinations of the said device and parts as described in the said specification, nondo we confine ourselves to the exact details of the construction of t-hesaid parts as illustrated in the accompanying drawings.
With the foregoing and other objects in view, which will be made manifest in the following detailed description, reference is had to the accompanying drawings for the illustrative embodiment of the invention, wherein:
FIG. 1 is a fragmental sectional view of the rollers of the rotary punching. machine showing the dies in hole punching position.
FIG. 2 is a fragmental sectional view of an end of the female die indicating the serrations.
FIG. 3 is a sectional view, taken on the lines 3-3 of FIG. 1, and
FIG. 4 is a fragmental perspective view on a somewhat enlarged scale of an end of the male die, showing the relief at its end.
In rotary punching machines of the type herein there are provided generally cylindrical rollers 1 and 2 driven in opposite directions to one another so that their adjacent surfaces move in the same lineal direction and at the same lineal speed. In other Words, if the top roller 1 is moved in contraclockwise direction, then the bottom roller 2 is driven'in clockwise direction and thus the adjacent surfaces will move to the right viewing FIG. 1 of the drawings herein. Usually one of the rollers has thereon the male punching die and the other the corresponding female punching die and the operation is so synchronized that the male die enters the female die at the proper time gradually with minimum penetration but shearing action against the corners or edges of the female die and thereby cuts out a hole or slot of predeter- 3,03 L905 Patented May 1 1,952
2 mined shape and size from a blank 3 passed between the rollers. Theblank 3 is fed in any suitable manner or by the friction contact with the die surface.
In the illustrative embodiment herein each roller is mounted on a shaft 4. Qn each shaft there are plurality of'supporting hubs or rings 6. The periphery of each hub is provided with one or more annular dovetail slots 7. Into the dovetail slots or grooves 7 extend and are suitably held dovetail heads 8 of bolts '9 extended through a base plate 10, on which latter are suitably mounted the respective female dies 11 or male dies 12, as the case may be. The centers of the roller shafts 4 are so spaced that as the respective male and female dies approach each other, there i aminimum of penetration by the male die into the cavity of the female die and the penetration is gradual as the respective peripheral portions meet and pass one another.
Both the male die 11 and the female die 12 are fixed on their respective base plates 1i) but it is preferable that the securing meansbe detachable, such as by screws or bolts, so that the dies may be interchanged. V The male die 12 has a removable wearing shoe 13 secured on its cutting face by suitable screws '14. This icutting face and the wearing shoe 1?: of the male die or cutter 12 is arcuate longitudinally of the motion of the male die and generally concentric with the shaft.
The female die 11 has a cutting face 16 with cutting edges also arcuate concentrically with its shaft 4 and longitudinally of the direction of its movement. The spacingofthe rollers or shafts is such that the generally symmetrical longitudinal arcs of the male die and ofthe female die are substantially tangential with very slight overlap, so that the male die does not enter the female die aolng its entire length at once, but penetrates gradually first at its leading end and then gradually toward its trailing end, and each point thereof penetrates when it is about tangential with the female die and emerges from thefemale die immediately after it performed" the cutting I operation. This action and step prevents the stickingor distorting of the male die and the cut.
A relief 17 is provided above the cutting edge of the leading end and also of the trailing end ofthernale die to permit the corners of the male die to move on an are which substantially clears the adjacent edges of the out p hole without engaging and dragging the sheet and thus prevents deforming the edges of the punched hole.
The plate or support 10 for the female die 11 is curved and cut away on its underside at its opposite ends, namely at the leading or trailing ends 18 under each female die 11 and it provides thereat a rounded and enlarged entrance corner 19 and an exhaust corner 20 respectively. Thus the space between the shaft and the underside of the plate 9 adjacent the outlets of the female die at the central portion of the plate 10 forms substantially a throat to produce a venturi-like eifect as the roller rotates. This not only leaves the corners under the plate 10 unobstructed to allow the easy removal of the cutouts but it also creates somewhat accelerated air current as the die rotates for blowing out the cutouts as they are released from the bottom of the female die.
In order to prevent the springing of the cutouts out of the female die, each end wall 21 of each female die is provided with suitable serrations or teeth 22. In the preferred form each of these teeth 22 is somewhat similar to a ratchet tooth. Each tooth 22 has an inclined side 23 facing toward the male die and toward the cutting edge of the female die and this side 23 is inclined inwardly of the female die so as to facilitate the pushing of the cutouts inwardly of the female die. The lower face 24 of each tooth 22 is generally straight and is generally at right angles to the adjacent wall of the female die so as to hold the end of the cutout in place and against upward springing. The inner end 26 of the cavity of the female die is enlarged or relieved so as to make certain that the cutout pushed to said inner end 26 is ejected therethrough.
The method steps involved in the manipulation to accomplish such clear cutouts include the substantially tangential contact between arcuate male and female dies acting on the blank so that the male die gradually penetrates into the sheet material between the dies, and arcuate pressure exerted upon the cutout to push it into the female die and push its ends against the adjacent walls of the female die; and then frictionally engaging the edges of the cutout in the female die so as to prevent the cutout from springing out; and then pushing the cutout further inwardly into and through the female die by subsequent cutouts being cut and pushed in superimposed position into the female die; and then exerting a venturilike action by the rotation of the die with its roller for facilitating the disengagement and discharge of the cutout from the machine.
The dies may be of suitable shapes for punching slots or holes of various shapes and sizes. In some instances it may be advantageous to have serrations preformed or preserrated in a separate friction element which is then inserted in the cavity of the female die so as to form an inwardly enlarging frictional wall of said cavity.
In operation the sheet material, such as card board or fibre board is fed between the rollers and it rests on the female die 11 and is slightly raised thereby. The leading edge of the male die penetrates into the leading end of the female die and as the arcuate dies move generally tangentially and concentrically to their respective roller centers, the following portions of the male die and female die interengage with minimum penetration and cut a hole of desired contour into the sheet, which latter is passed along between the rollers. The cutout from such hole is pushed into the female die leading end first so that the cutout is arched generally oppositely to the arc of the female die and is frictionally held against springing out or escaping until it is pushed through the female die by subsequent cutouts. The release of the cutout at the bot tom accelerated by the venturi-like action created under the female die by the cutaway ends of the underside of the female die holder plate.
In a device for cutting an aperture in a blank and handling the cutout from such aperture, a female die 7 generally tangential relation, moving generally in the same lineal direction at the tangent points, the arc of each of said respective arcuate edges is generally centered on the respective rotatable supports, and said arcs being generally longitudinal with respect to their direction of movement and being located at opposite sides of said blank, each of said rotatable supports including a roller shaft, a retaining ring fixed on the roller shaft at each die location and a die holder plate secured to said retaining ring in spaced relation to said shaft to hold the respective die in position, and friction elements formed on the walls of said die cavity for frictionally engaging the respective edges of said cutout as said cutout is pushed into said cavity by said male die, the die holder plate for the female die being extended beyond an end face of said ring and having an aperture therethrough communicating with said die cavity so as to form ejection space for the cutouts between said die cavity and the adjacent shaft, the underside of the leading and trailing ends of said female die holder plate being cutaway so as to taper from the respective ends inwardly toward said aperture thereby to accelerate the airflow through the space below said female die cavity for accelerating ejection of the cutout from said cavity.
References Cited in the file of this patent UNITED STATES PATENTS 1,110,238 Spiegel Sept. 8, 1914 1,729,123 Philip Sept. 24, 1929 2,264,134 Hawley Nov. 25, 1941 2,404,793 Dickerman July 30, 1946 2,526,741 Goemaere Oct. 24, 1950 2,604,167 Oliver July 22, 1952 2,677,422 Novick May 4, 1954 FOREIGN PATENTS 534,443 Great Britain Mar. 6, 1941 665,178 Great Britain Jan. 16, 1952