US2287882A - Punch - Google Patents

Description

- June 30, 1942. 4 c, F 2,287,882

PUNCH Filed April 25, 1941 5 *D- A 4 T155 1 L /9 E fi 7 I '2 v 9- I Patented June 30, 1942 2,287,882 PUNCH Lyman O. Huff, Chicago, Ill., assignor to Universal Oil Products Company, Chicago, 111., a corporation of Delaware Application April 25, 1941, Serial No. 390,289

Claims. (01.164-124) The invention relates to an improved form of punch of a general type which comprises a holder and one or more removable punching members or punch inserts, such as used, for example, in punch presses, pilling machines and the like.

It is common practice in apparatus of the class above mentioned to retain the removable punching member or members in the holder by means of a set screw or screws threaded into the'holder and bearing against the shank of the punch. Such an arrangement is particularly desirable since it permits the replacement of broken or damaged punching members without replacing the entire assembly or the holder. I have found, however, that when a punch breaks the break most frequently occurs eitherat the face of the holder or at the approximate elevation of-the set screw. In either case it is extremely difllcult to remove the upper stub of the broken punch from the holder.

The invention obviates the disadvantage above "mentioned by providing the removable punching member with a weakened section in its shank, said section being disposed at a point where the punching member may be broken to the best advantage from the standpoint of facilitating its removal from the holder.

When, as is usually the case, the holder is provided with a set screw for retaining the punch in place, the weakened section of the shank is disposed outwardly or toward the face of the holder with reference to the point at which the shank is contacted by the set screw. In such instances, I preferably provide a recess in the holder extending from the set screw port to the top of the well provided in the holder for the reception of the punch or, alternatively, I cut away a portion of the shank of the punching member from its inner endto a point thereon corresponding to the elevation of the set screw.

With this last mentioned provision, pressure exerting means, such as a grease gun or the like, may be'secured to the holder at the set screw port, after the set screw is removed therefrom, to force cup grease oil or other suitable fluid into the punch recess and exert an outward pressure on the broken stub of the punch to expel it from the holder.

Alternatively, the weakened section of the punching member may be disposed at a point therein which is outside the holder when the punch is in place in the latter so that the break occurring at the weakened p rtion will leave a grasped with pliers or the like to remove it there- Iv from.

The features and advantages of the invention will be more clearly understood with reference to the accompanying diagrammatic drawing, comprising Figures 1 to 6 inclusive, which illustrates the invention in several of the specific forms which it embodies.

Figure 1 of the drawing is an elevational view of a punch and punchholder with the latter shown in longitudinal section,

Figure 2 is a cross-sectional view of the punch and punch holder shown in Figure 1, this section being taken along line 2-2 in Figure l.

Figure 3 illustrates a portion of a modified form of punch embodying the features of the invention.

Figure 4 is an elevationalview of another modified form of punch and punch holder with the latter shown in longitudinal section.

Figure 5 is a cross-sectional view of the punch and punch holder shown in Figure 4, this section being taken along the line 55 in Figure 4.

Figure 6 is an elevational view of another .modified form of punch and punch holder with the latter shown in longitudinal section.

, Referring to Figures 1 and 2, the punch holder 4 is designated by the reference numeral l and is provided with a relatively deep recess or well for the reception of the removable punching member 2 and is also provided with a threaded port 3 communicating with the punch recess and dis- 1 posed transversely thereto at a point between the inner end of the punch recess and the face of the holder from which the punch protrudes. A set screw 4 is provided in port 3 to bear against the shank of the punch within the recess and retain it in place in the holder.

In the particular instance illustrated in Figure 1, the removable punching member 2 is provided adjacent its upper end with a suitable notched or flattened portion 5 against which the set screw 4 is adapted to bear. A small segment is cut from the punching member, as indicated at 6, ex'-. tending from the inner end of the punch to the portion 5 thereof, to provide a continuous passageway from port 3 to the inner end of the punch recess when the punch is in place in the latter.

Anotch, indicated at l in Figure 1, is provided in the shank of punching member 2 at a point between section 5 thereof and the face of the holder. Notch lis of such form that the punch is weakened more at this point than at'section stub protruding from the holder which can be 5, so that breakage of the punch will occur adjacent the notch I rather than adjacent section 5. In the case here illustrated, the depth of the notched portion at is substantially the same as the depth of the notched portion I, as indicated by the dimension B in Figure 1, but the relatively flat bottom of notch 1, indicated by dimension A in Figure 1, is shorter than the relatively fiat section B at 5. Thus, stresses which tend to break the punch are more concentrated adjacent section I than adjacent section 5 and breakage will occur at the latter point.

To'remove the stub of a punch, such as illustrated in Figure 1 after it has broken adjacent the notch I, the set screw 4 is removed and suitable pressure exerting means, such as, for ex-- ample, a grease gun, not illustrated, having a threaded fitting at its outlet end to screw into port 3, is attached to the holder and cup grease or other suitable fluid is forced therefrom into the open portion of the punch recess formed by the notched out portion at 5 and passageway 6. The pressure thus exerted against the bottom of the notched portion 5 will start the punch from the holder and admit fluid from passageway 6 between the top of the punch and the end of the punch recess, forcing the broken stub from the holder.

In Figure 3, the modified form of removable punching member, here illustrated, is designated by the reference numeral 8 and difiers from member 2 of Figure 1 in that the weakened section of the punch at which it is most likely to break is formed by a continuous groove 9 which gives the shank of the punch a section C of smaller cross-sectional area than the section D adjacent the segment removed from the upper end of the punch. In the case illustrated in Figure 3, the portion removed from the punch the holder that when a break occurs adjacent the groove, the protruding stub may be grasped with a pair of pliers or the like to remove it from the holder.

ing members in a single holder) as well as to. sin-' gle punches such as illustrated.

The term punch or punching member" as used in the specification and appended claims "should not be interpreted as limiting the invenshank to provide a bearing surface for the set screw is of continuous thickness from adjacent its bottom to the upper end of the punching member and functions in much the same manner as the section 5 and fluid passageway 6 in has no flattened or cut away portion for the set screw it in holder I 4 to bear against. However, there is still likelihood that the punch will break adjacent the set screw and to avoid this a notch l5, similar to notch l in Figure l, is provided in the shank of the punch beneath the point where the set screw bears against the shank. Inasmuch as the punching member of Figure 4 has only one weakened section which is adjacent notch l5, it need not be weakened to such an extent as the punches of Figures 1 and 3. Hence, the punch is proportionately stronger and will normally operate for a longer period of time without breaking In the c'aseillustrated inFigure 4, instead of cutting away a portion of the shank of the punch adjacent its upper end to form a fiuid passageway from the set-screw port Hi to the upper end tion to members which pierce or make indentations or openings .since the invention specifically contemplates the adaptation of its. features to compressing and pilling machinery or the like in which the punches act as compressing, pilling or ejecting members.

I claim as my invention:

1. A punch of the class described of substantially the same diameter at both ends having a section of reduced cross-sectional area adapted to be contacted by a set screw for retaining the punch in a holder therefor, and having a second section of greater weakness than the first named section disposed intermediate the first named section and the outer end of the punch.

2. The punch defined in claim 1, wherein the second section is weakened by a notch.

3. In apparatus of the class of punching, pilling and the like machines; the combination of a punch holder, a removable punch having a shank disposed in a recess provided in said holder, the

holder having a port in its wall communicating with said recess and threaded for the reception of a, set screw for the punch, the punch having a weakened portion disposed between the point where it is contacted by the set-screw and the outer end of the punch, said weakened portion being of less diameter than the diameter at said point and the diameter at said outer end.

4. In apparatus of the class of punching, pilling and the like machines, the combination ofa punch holder, a removable punch having a shank disposed in a recess provided in said holder, the holder having a port in its wall communicating with said recess and threaded for the reception of a set-screw for the punch, the punch having a weakened portion disposed between the point where it is contacted by the set-screw and the face of the holder, and means for establishing communication between the set-screw port and the innerend of the punch recess.

5. In apparatus of the class of punching, pilling and the like machines, the combination of a punch holder, a removable punch having a shank disposed in a recess provided in said holder, the

holder having a Port in its wall communicating with said recess and threaded for the reception of a set screw for the punch, the punch having a weakened portion disposed between the point where it is contacted by the set screw and the face of the holder, and the holder being provided with a fiuid passageway in its recess-defining wall extending from the inner end of the latter to and communicating with the set screw port.

6. In an apparatus of the class of pilling, punching and the like machines, the'combination of a punch holder, a removable punch having a shank disposed in a recess provided in said holder, the holder having a threaded port in its wall communicating with said recess and threadedly receiving a set-screw [or the punch,.the'

punch having a weakened portion disposed between the point where it is contacted by the setscrew and the face of the holder, that portion of the punch extendingv from its inner end to adjacent the set-screw port in the 'holder being constructed and arranged to provide a fluid passageway from the set-screw port to the inner end of the punch recess.

'7. A punch of substantially uniform cross-sectional area having a longitudinally extendingportion of reduced cross-sectional area extending from an intermediate point to one end thereof and another portion of reduced cross-sectional area disposed between the first named portion and the opposite end of the punch, the second named portion being weaker than the first named portion, and being less in cross-sectional area than said opposite end.

8. A punch of the class described, a segrnent of its shank being of relatively reduced cross-sectional area at and adjacent one end thereof,

said punch also being provided'with a recess therein at a point between the aforementioned section of reduced cross-sectional area and" the opposite end of the punch, a section through the punch at said recess being weaker than any other section thereof, and being less in cross-sectional area than said opposite end.

9. A punch of substantially uniform cross-sectional-area throughout itslength, having a section of reduced cross-sectional area intermediate its ends in the form of a recess adapted to receive the end of a set-screw, said punch having another portion of reduced cross-sectional area extending from said recess to one endof the punch and having a portion of reduced crosssectionalarea disposed between said recess and the opposite end of the punch, the punch being weaker at the last described portion than at any other portion thereof, and being less in crosssectional area than said opposite end,

10. A punch of the class described having a section of reduced cross-sectional area adapted to be contacted by a set screw for retaining the punch in a holder therefor, and having a second section weakened by an annular groove disposed intermediate the first-named ,section andthe outer end of the punch.-

' LYMAN C. HUFF.

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