US3015161A - Punch device - Google Patents

Description

Jan- 2, 1962 H. SEMLER ETAL PUNCH DEVICE Filed Aug. 18, 1958 United States Patent Ollice 3,015,161 I Patented Jan. 2, 1962 PUNCH DEVICE Loren H. Semler, Chicago, and Curt E. Nyberg, Skokie,

Ill. ,assignors to Metal Specialties Manufacturing Co., Chicago, 111., a corporation of Illinois I Filed Aug. 18, 1958,.Ser. No. 755,719 4 Claims. (Cl. 30-363) This invention relates to a punch device, and more particularly to a punch device of the plier type in which a pair of members each providing a jaw and a handle are pivotally connected together at an intermediate point.

In the usual punch structure in which the handle and aw pottions are formed of metal, the two-members beng connected at a central engaging point by a pivot pin, it is found that under heavy punching operations, where a large number of sheets are being perforated, the metal parts tend to become deformed slightly and to retain their set in the deformed position,. .A slight misalignment makes the punching operation difiicult, causes excessive wear of the die and punch parts, and often makes the structure un'servicea-ble. Because of the difficulty in operating the sprung punch,the punch isoften discarded.

We have discovered that a highly effective punch device can be produced through the use of resilient plastic material property which will permit slight yielding of the jaw portions in thepunching operation even when the load is very heavy as when a large number of sheets are being punched, and .then will restore the punch parts to their original shape after the punching actionfFurther, the resilientcharacter. of the jaws, etc, is efiective in better alignment andcutting action, and with such structure a one-piece stripper and die member can beeifectively employed and a cap receptacle frictionally' held for receiving the punched segments or caps. We have further' foundgthat in a plier. type-punch better action is obtained by .disposing the pivot pin off center and more nearly in horizontal alignment with one of thejawsf An object of the present invention is to provide the structure described above and bring about the new results and. advantages. referred to. Another object is to provide in a punch device resilientmembers which permit high pressures to be employed in the cutting of a plurality of paper plies While at the same time immediately restoring the parts to their original shape and position after the release of pressure. A still further object is to provide yielding jaw means which support and facilitate the action of the punch member in combination with the die member. Another object is to provide in a plastic punch structure a one-piece, U-shaped stripper and die member adapted to be anchored to one of the jaws of the punch while also providing a cap receiver adapted to frictionally engage the lower portion of the plastic jaw. Yet another object is to provide sturdy means for supporting a pivot pin within engaging portions of the jaw and handle members and resilient spring and handle means for operating the jaws. Other specific objects and advantages will appear as the specification proceeds.

The invention is shown, in an illustrative embodiment, by the accompanying drawing, in which- FIGURE 1 is a perspective view of a punch device emobdying our invention; FIG. 2, an enlarged longitudinal sectional view; and FIG. 3, a perspective view of the one-piece stripper and die member.

In the illustration given, A designates a plastic member providing a handle portion and a jaw portion 11; B designates a member providing a handle portion 12 and a jaw portion 13. The member B is provided near its forward portion with a circular body portion 14 adapted to receive a pivot pin 15. The portion 15 is received within a hollow portion of the member A, and the pin 15 extends through the two members A and B so as to pivotally connect the same in the position shown in FIGS. 1 and 2.

The jaw 13 of member B carries a punch pin or cutter pin 16 provided with a pressure plate 17 adapted to rest against the. inner face of the jaw 13 and an integral retainer pin 18 extends through an opening 19 in the jaw and at its top is peened to form a retainer flange 20.

The lower jaw 11 is provided with an aperture 21 for receiving cut segments or caps, and is preferably providedat its bottom with a resilient lip22 adapted to frictionally engage the yieldingresilient flange portion 23 of a plastic cap receptacle 24. The jaw 11 is preferably recessed to receive a U-shaped metal stripper and die member 25, and pins 26 extend through openings in the lower leg of the member 25 and through the plastic jaw 11 for anchoring the member 25 in the position shown in FIG. 2. The stripper member is provided with a recess 27 adapted to receive the punch pin 16, and at its forward end with a guide member 28. If desired, the stripper may be provided with additional recesses 29 and 30, as illustrated best in FIGS. 2 and 3..

The lower leg of the member 25 is provided with. a die opening 31 adapted to receive the punch pin 16 and to guide the punch pin as it travels downwardly in the cutting operation. As shown best in FIG. 1, we prefer to provide the upper jaw 13, and on each side thereof, with a scaleindicated by the numeral 32, so that in the.

punching operation an accurate punchingof holes can be made in several punching operations, the user being thusable'to accurately punch successively holes in sheets which are later to be brought into alignment. By the scale located, as shown, directly above the stripper and 1 die member 25,it is possible to punch the holes uniformly in sheets which are fed successively to the punch device.

By employing a tough resilient plastic material in the fomain'g of. the jav'vand handle members, we have found thatthe' punch devicehas much longer life and operates uniformly through its life and without tendency vto become deformed, as has heretofore been the experience with metalpunches. The plastic resin employed is preferably one of'elastic type sothat after the bending under high pressures during the punching action, the plastic members will rebound to their initial shape. Any suitable' plastic resin having the necessary strength and having the elastic property above referred to, may vbeemployed. For example, acrylonitrile plastic gives the'necessary strength, while at the same time providing the elastic property required to restore the parts immediately to their initial shape after the release of pressure. Styrene plastic filled with fiberglass has the necessary strength and the rebound that is needed. Obviously, other plastics such as nylon, polyethylene, and a variety of plastic resins having elastic properties, may be employed. Since such resins are well known, a further detailed description herein is believed unnecessary.

We have discovered that more effective cutting action is obtained where the pivot pin 15 is below the center of the engaging members A and B. In the specific illustration given, the drop from the center is approximately .060, and it will be observed that the pin now extends below the top surface of the lower jaw 11 and in horizontal alignment with the lower jaw. With this structure, the punch pin 16 strikes the paper to be perforated at an angle and enters the die opening 31 along one side, so that the die opening itself can serve as a guide for the pin 16 in its downward travel. Since the jaws are resilient, the pin and die, when engaged, are permitted by the jaws to travel in true alignment with each other.

The handle portions 10 and 12 are preferably hollow and are provided with central reinforcing walls 33, and a compression spring 34 is effectively housed between the wall 33 and adjacent side wall of each handle member 10 so as to limit the inward movement of the plastic handle members.

Operation In the operation of the punch device, the paper to be punched is inserted within the mouth of the stripper and diemember 25and in the desired alignment with the scale 32 thereabove and the handle members and 12 are then squeezed in the usual manner. The'resilient jaws 11 and 13 move uniformly in an arc and the lower portionof the punch pin 16 presses into the paper and into thedieopening 3-1. The die and pin automatically align themselves with the jaws yielding slightly during the re sulting linear cutting action. The flex in each handle maintains'the relative jaw positions so that the alignment of the punch and die will be on the same are of the circle. Even though a large number of sheets are punched and the strain upon the jaws is heavy, an effective severing operation is accomplished and immediately upon the re lease of pressure, the jaw and handle portions spring back to the original position. Thus, while the resilientjaws provide the necessary strength for supporting the punch and die parts, they enable the parts to telescopically engage at wider angles for more effective severing of the paper, while then yielding so that the parts are guided in telescoping relationwith each other and after the severing action "and when the pressure is released, there is an immediate rebound of all of the plastic parts to their original position and with no permanent deformation therein. Repeated operation may, therefore, take place and with the parts always operating in the same uniform manner.

The stripper and die member'ZS reinforces thelower jaw, maintains the sheets to be severed in proper alignment with the lower jaw, and strip the paper from the punch after the cutting operation. The jaw-further provides resilient 'flange portions ZZforgn'pping the resilient lip portions 23 of the receptacle so thatthe receptacle is frictionally held tightly in place during the punching operation, butfis removable for emptying the caps.

While, in'the foregoing specification, we have set forth in considerable detail a description of one embodiment of the invention, it will be understood that such details of structure maybe varied widely by those skilledin the art without departing from the spirit of our invention.

'We claim:

, v 4' 1. In a punch device havingopp'osed rigid meta'l punch in and die elements and handles pivotally connected together, "resilient jaws carried bysaid handle members and supporting said pin and die elements, said jaws being of plastic resin having elasticity whereby said jaws flex under high pressure during a punching-action and completely recover their original shape upon the release of said high pressure. 1 I

2. The-struotureof claim 1 in whichasaidhandles are equipped with inwardly-extending stop members which limit the degree of fiexofsaid jaws.

3. The structure of "claim "1 in which said jaws and handles are formed ofacrylonitrile plastic.-

'4. A punch, comprising a pair of longitudinallyextending members pivotally connected at an'intermediate point, each of said membershzlving a'han'dle portion and a jaw-portion and with the jaws extending in opposed relation, said jaws and handlesbeing'formed of a plastic resin having elasticity, a punch pin secured to the end portion of one jaw and extending inwardlyja metal die secured to the other jaw and adapted to receive said punch pin, a pivot pin 'pivotally connecting said members in offset "relation from the engaging centers of said membersandin general alignment with said die, said jaws being of such dimensional-cross section as to cause them to flex during punchingaction and completely recover their original shape "after the release of punching pressure, and stop means carried by said handles limiting the degree of flexing of said jaws.

References Cited in the file ofthis patent UNITED 'STATES PATENTS Drake Jan; 5,31-869 OTHER'REFERENCES S chack: .A Manual of Plastics and Resins, Chemical Publishing Co., 1950, page 149 relied on. OPY in Div.50.') v

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