US2526741A - Self-cleaning punch - Google Patents

Description

Oct. 24, 1950 R. L. GOEMAERE 2,526,741

SELF-CLEANING PUNCH Filed May 27, 1949 INVENTOR. 055 2; 1. 606440595 Patented Oct. 24, 1950 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to devices for removing material from work and particularly to an improved self-cleaning punch for cutting sheet material.

In operating upon sheet material such as cardboard trim panels and other similar kinds of sheet material, it has been the practice to use a punch for cutting holes through the sheet material through which various elements may be passed. Heretofore, the punching out devices employed for such purposes have been rather small in size and slow in operation and required periodical removal of the device to clean out the severed portions of the sheet material therein. Where attempts have been made to out out larger sizes of openings in the sheet material, the punching out devices clogged and slowed in use.

An important object of this invention is to provide an improved self-cleaning punch which quickly and cleanly removes the cut out blanks of the sheet material and which will operate indefinitely and without the necessity of periodically removing the punch to clean out the blanks collected therein. Another important object of the invention is to provide a punch of this character which is provided with a leading cutting edge for severing the sheet material and cutting a blank therefrom and further provided with an interior secondary cutting edge which subdivides the cut out blanks so that they may be readily discharged from the punch. A further important object of the invention is to provide a punch of this character which is economical to manufacture and easily installable for operation.

A self-cleaning punch constructed in accordance with this invention preferably comprises a one-piece member of generally cylindrical constructure provided at the lowerend thereof with a cutting edge, usually circular in character, and a central passageway leading up from the cutting edge and dividing into two diverging passages through which blanks cut out from the sheet material are passed. Within the interior of the body there is provided a novel cutting edge extending preferably diametrically to the circular cutting edge but recessed thereabove and located between the branching passages so that as the blanks commence to pass therethrough they are severed into smaller sections. In the preferred form of the invention the secondary cutting edge is located at the juncture and forms the common meeting edge of the two passages.

Various other objects, advantages and meritorious features of the invention will become more fully apparent from the following specification, appended claims and accompanying drawings, wherein:

Fig. l is a top plan view of a vertically reciprocating part of a punch press illustrating the mounting of the self -cleaning punch therein and its relationship to the die-board in which it is secured,

Fig. 2 is a vertical cross sectional view through the punch press machine illustrating the position of the self-cleaning punch therein and the two cutting edges thereof,

Fig. 3 is a vertical sectional view taken along line 33 of Fig. 1 and being 90 to that illus trated in Fig. 2, and

Fig. 4 is a fragmentary sectional-view similar to the central portion of Fig. 2 illustrating the self-cleaning punch in operation and the manner in which the cut blanks are removed therefrom.

The apparatus in which the self-cleaning punch is located comprises a fixed base support II] which is usually flat for receiving a sheet of cardboard trim panel or other severable material l2. Surmounting the fixed support In is a vertical reciprocating body including a horizontal extending die-board I4 in which is fixed a selfcleaning punch generally indicated at It constructed in accordance with this invention. The self-cleaning punch'reciprocates jointly with the die-board l4 and the lower end thereof is brought into engagement with trim panel l2 for cutting a blank thereout. The die-board l4 and the punch l6 may be secured to the underside of any suitable type of reciprocating member, ram or other moving part of a punch press.

The body of the self-cleaning punch is preferably formed in one piece of cast metal and has a general cylindrical formation. The lower end of the punch body is provided with a circular cutting edge [8 which is adapted to penetrate the trim material and cut out a circular blank therefrom. The interior of the body I6 is hollowfor part way above the cutting edge I8 and forms a central vertical passage 20 extending to upwardly approximately mid-way between the upper and lower ends thereof. The passage 20 is divided at approximately the middle of the body into two diverging branches 22-22 of corresponding shape and formation. These last two branching passages open out through the upper end portion of the body at the corner formed between the top face 24 thereof and the circular side wall thereof. Opening out in this manner, the branch passages leave a considerable area of the top face 24 for direct engagement with the lower side of the reciprocating member or ram to which the die-board It is secured.

The two passages 2222 each have a width in one dimension less than the diameter of the blank cut by the punch and the passage and normally neither one of these branches would be able to take the circular blank cut out by the punch. To further subdivide the circular blanks cut out by the punch in order that these subdivided sections may pass through the branches 22-22, there is provided a second cutting medium. As shown in Fig. 2, the walls of the branch passages convergingly slope toward one another and join together to form a downwardly tapered centrally located boss terminating in an apex 26 extending across the main passage. The boss serves as a sturdy carrier or support for the second cutting medium and as illustrated herein the common meeting edge or juncture line 26 is utilized as the secondary or supplemental cutting edge. This cutting edge, as shown in dotted outline in Fig. 3, preferably extends straight acros the circular larger passage 20 and diametrically thereof so as to bisect the blanks cut out by the leading edge l8. The subdividing or bisectin operation is shown in Fig. 4, wherein a stack of cut out blanks 28 from previous cutting operations is shown advancing upwardly through the punch and being severed by the interior cutting edge 26. The subdivided sections of the circular blanks are fed upwardly through th branch passages 2222 and eventually are discharged from the punch. To facilitate the discharge of the cut blanks, the die-board I4 is preferably shaped in the manner shown in Fig. 1 to provide openings 30-30 on opposite sides of the punch press. As shown in Fig. 1, each branch passage 22 aligns with one of the openings 30 so that as the cut blanks are accumulated they are forced by pressure of additional blanks out of the passage 22 and through the adjacent opening 39. The cut blanks will fall upon the platform !0 and may be swept away at convenient times between th removal of one sheet I2 and the replacement of a new sheet thereon.

There is associated with the self-cleanin punch a pair of resilient members 32-32 on opposite sides of the punch and corresponding in shape and formation to one another. These resilient members are preferably composed of rubber and are secured at their upper ends by adhesion or otherwise to the under side of the dieboard M. These rubber elements are of such length as to project below the leading cutting edge I8 of the punch as shown in Fig. 3. In operation of the device, these rubber members 32 are compressed by their engagement with the sheet material [2 and contract as the cutting edge !8 pierces the sheet material. As the punch is lifted from the cut material the members 3232 resiliently expand and force the sheetmaterial away from the punch.

Although the punch body illustrated herein is shown as cylindrical and provided with a circular cutting edge [8, it is understood that the punch body may be of an oval or a generally square 01 rectangular formation in order to cut oval, square or rectangularly shaped holes in the sheet material [2.

What I claim is:

1. A self cleaning punch device comprising, in combination, a hollow body interiorly shaped to form a main passage opening out through the bottom portion thereof and at least two branch passages communicating with the upper end of the main passage and extending upwardly and outwardly away from one another and opening out through the side wall of the body adjacent to the upper end thereof, a continuous cutting edge surrounding the bottom opening of the main passage and adapted to cut out blanks from sheet material upon which the punch operates and to successively feed the cut out blanks into the main passage, a second cutting edge located in said main passage adapted to sever the blanks received therein into smaller sections, a supporting memher for the punch body secured to the upper portion thereof for joint movement therewith, said supporting member being wider than the punch body and provided with downwardly opening recesses aligning with the opened upper ends of the branch passages to facilitate discharge of the severed sections of the blanks escaping therefrom.

2. A self cleaning punch comprising, in combination, a. hollow body having a substantially closed upper end forming a relatively flat top face and provided on the lower end with a continuous cutting edge adapted to cut a blank out of sheet material upon which the punch operates, said body being shaped interiorly to provide a main passage opening out through the lower end thereof through the area defined by the cutting edge for receiving successive blanks cut by said edge and having a cross sectional area at least equal to that of the blank cut out of the sheet material, said main passage extending upwardly from the cutting edge and dividing interiorly of the body into at least two upwardly and outwardly diverging subsidiary branch passages each having a cross sectional area less than that of the main passage, the upper ends of the branch passages opening out through the side wall of the body immediately adjacent to the top face thereof, said branch passages having sloping walls converging together and forming a downwardly tapered boss in the central part of the body, a supplementary cutting medium carried by the boss and operable to sub-divide the blanks into smaller sections, and a die-board extending fiush with the top face of the punch body and connected to the upper end thereof, said die-board provided with downwardly opening recesses aligning with the upper opened ends of the branch passages to facilitate the escape of the severed sections of the blanks discharging therefrom.

3. A self cleaning punch comprising, in combination, a hollow body having a substantially closed upper end and provided on the lower end with a continuous cutting edge adapted to cut a blank out of sheet material upon which the punch operates, said body being interiorly shaped to provide a vertically extending main passage opening out through the lower end of the body through the area defined by the cutting edge for receiving successive blanks cut by said edge, the cross sectional area of said main passage throughout its length being at least equal to that of the blanks cut out of the sheet material upon which the punch operates, a downwardly tapered boss in the upper end portion of the main passage and constituting an integral part of the body, said 5 6 boss having sloping walls converging to an apex REFERENCES CITED on the lower end P and subfhvldmg the The following references are of record in the upper portion of the main passage into at least file of this patent. two upwardly and outwardly inclined branch passages, said branch passages communicating 5 UNITED STATES PATENTS at theirlower ends with the main passage and Number Name D t opening out through the side wall of the body a 153,556 Fisher July 28, 1874 their upper ends and each having a cross sec- 1,129,079 Donaldson Feb. 23, 1915 tional area less than that of the mai pa g 1,309,157 Stockman July 8, 1919 and a supplemental cutting medium carried on 10 1,321,896 Davis Nov. 18, 1919 the lower apex end of the boss and operable to sub-divide the blanks received by the main passage into sections of a size to pass through the branch passages.

RUSSELL L. GOEMAERE. 15

Images