US2735492A

US2735492A - Hand punch

Info

Publication number: US2735492A
Authority: US
Publication date: 1956-02-21
Anticipated expiration: 1973-02-21

Description

Feb. 21, 1956 s. CAIN 2,735,492

HAND PUNCH Filed Sept. 2, 1954 All/W HAND PUNCH Stanley Cain, Fox Lake, 11]., assignor to McGill Metal Products Company, Marengo, 11]., a corporation of Illinois Application September 2, 1954, Serial No. 453,304

2 Claims. (Cl. 164121) This invention relates generally to improvements in a hand punch and more particularly relates to a hand punch having a stripper bar provided with novel means for limiting the spreading movement of the jaws of the punch.

Punches of the type with which the invention is concerned are constructed to punch holes of desired configuration in sheets of paper or cardboard by squeezing the handles of the punch together. It has been known to provide a stripper bar secured between the jaws of the punch to facilitate removal of the paper or other article operated upon by the punch. Likewise, it has been known to install a member such as a bar, plate, rivet or the like adjacent the inner ends of the jaws of the punch effective to limit the distance which the jaws may be spread. However, to the best of my knowledge, achieving both these results has been accomplished by the use of two separate and distinct structures which by their nature have contributed substantially to increased cost of the hand punch.

Accordingly, it is a principal object of the invention to provide a hand punch of the character described in which the stripper bar is provided with novel means integrally formed therewith for restricting the amount the jaws of the punch may be spread, such stripper bar being characterized by its substantially reduced cost of manufacture.

Another important object of the invention is to provide such a hand punch having the improved stripper bar described herein in which said means comprise an upstanding lug or car cut or punched out from the body of said stripper bar, said stripper bar being secured to one of the jaws of the punch and the lug or car having its free end outwardly bent and disposed to engage the other jaw to stop or limit spreading movement of the jaws.

Another object of the invention is to provide a hand punch of the character described in which the said stripper bar is provided with an elongate ofl'set end adapted to be received between the side flanges of a handle and secured to one of the jaws, the side flanges preventing lateral movement of the stripper by reason of the offset end received therebetween.

Other objects of the invention reside in the durable construction of the hand punch, the more easy and simple manner of installing the stripper bar and reduced likelihood of parts being deformed or broken.

In prior hand punches the stripper has served as a guide for the paper or card entering between the jaws to be perforated. Because of this usage the stripper nose is curved to follow generally the contour of the front of the jaw carrying the male punch member. The users vision is therefore limited because the female die is substantially hidden from the usual position of the users eyes during the punching operation.

An important object of the invention is to provide a stripper in which the opening enabling passage of the male punching member is elongate and continued forward to the nose of the stripper thereby giving a clear view of the female die, and hence the punched article in alignment Patent Q 2 with the. male die member, over a greater area than heretofore possible.

These and other objects of the invention will become apparent as the description thereof evolves. In order to enable the invention to be understood and practised by those skilled in the art to which same pertains, a preferred embodiment has been described in detail and shown in the accompanying drawing. It is contemplated that minor changes in the size, proportion, arrangement and construction of the various parts may be made withoutdeparting from the spirit or the scope of the invention.

In the drawing where the same reference characters have been employed to designate similar or equivalent parts throughout the several figures thereof:

Fig. 1 is a side elevational view of the hand punch embodying the invention.

Fig. 2 is a median sectional view taken through the hand punch along the line 22 of Fig. 3 and in the direction indicated.

Fig. 3 is a fragmentary plan view of the said hand punch.

Fig. 4 is a sectional view taken through the hand punch along the line 44 of Fig. 2 and in the direction indicated.

Fig. 5 is a fragmentary front elevational view of punch, i. e. looking in a direction toward the jaws of the punch.

Fig. 6 is a perspective view of the novel stripper bar employed in the hand punch.

Referring now to the drawing, the reference character 10 designates generally the hand punch embodying the invention. Same comprises a pair of

cross-levers

11 and 12 pivotally connected together by a pivot pin 13. The cross levers are stamped from sheet metal of suitably heavy gauge to the desired configuration. As viewed in Fig. 1, the portions of said levers extending to the right of the pivot pin 13 provide handles 14 and 15 and the portions to the left of said pin provide

jaws

16 and 17. The handles 14 and 15 are each channel-shaped providing sockets in the hollow of each for receiving two ends of the coiled spring 18, the end 19 being looped and dis posed in engagement with the pivot pin 13. The spring 18 is mounted between the handles under tension so as normally to urge the handles in a direction away from each other whereby the jaws normally will be separated.

The

jaws

16 and 17 also are channel shaped and will be referred to as the upper and lower jaws respectively. To the forward end of the web 20 of upper jaw 16 is riveted a depending male punch member 21 and in the Web 22 of lower jaw 17 is provided a female cutting die 23. Upon squeezing of the handles 14 and 15 together, the punch 21 is caused to enter the die opening 23 punching a perforation into the paper or other article disposed between the jaws.

The construction of the hand punch as described hereinabove is well known. The invention resides in certain novel improvements concerned with the stripper bar designated generally 30 shown in Fig. 6. Same is stamped from sheet metal in the form of an integral member including a fiat, body portion 31 having its forward end or nose upwardly bent with the side edges thereof converging. The end or nose 32 is curved to follow generally the contour of the front of the upper jaw 16 carrying the punch 21. An elongate opening 33 is provided in said body portion 31 which is continued and extended forward to the nose 32.

The opposite or inner end of the stripper bar 30 is bent downwardly at 34 to form an offset portion 35 provided with an opening 36. The extremity 37 of said offset portion is of reduced width as compared with the rest of said portion.

An ear or lug 38 is cut or struck from the body portion 31 of elongate formation and upstanding from said body portion at the bend 34. The free end 39 of said ear or lug is turned inwardly in a direction toward the nose 32 and arranged substantially parallel to and spaced above the body portion 31 and is in the nature of a hook formation.

Having described the construction of the stripper bar 30, attention is directed to Fig. 2 showing the manner in which same is installed. The bar 30 is disposed between the

jaws

16 and 17 with the body portion 31 substantially parallel to the plane of web 22 of the lower jaw 17 and the inner end of said bar arranged adjacent pivot pin 13. As shown in Fig. 2, there is a split sleeve 46 engaged around pivot pin 13 and the extremity 37 by reason of its reduced width is received between the

flanges

25 and 26 of the handle 16, almost flush against said sleeve. It will be noted that since the offset portion 35 is sufficiently long to extend between the

flanges

25 and 26 almost flush against the sleeve 40, the side edges of end 37, which are of reduced width, will bear against

flanges

25 and 26 preventing lateral movement of the stripper even though secured at only one place on lower bar 17. Bar 30 is secured on the inner end of the lower jaw by means of rivet 41 extended through the opening 36 and a suitable opening in the web 22. The nose 32 is positioned exterior of the front end of jaw 16 with the elongate opening 33 opposite punch 21 and permitting passage therethrough of said punch for engagement with die opening 23.

The ear or lug 38 extends upwardly toward the web 20 of upper jaw 16 and through the said jaw past the inner end 42 of said web. The book formation 39 is positioned over the web 20. As shown in Fig. 2, said hook 39 will engage the upper surface of web 20 restricting the relative spreading movement of the

jaws

16 and 17 oc casioned by the normal bias of spring 18 against handles 14 and 15. However, upon the handles being squeezed together, the lug or ear 38 is free to move with the lower jaw 17 past the web 20.

It will be seen that the stripper bar 30 enables many advantages to be attained. It is an integral member capable of being stamped out in one operation. The ear or lug 38 is sturdy and provides superlative stopping means for restricting spreading movement of the jaws. As noted in Fig. 5, since opening 33 extends forward to the nose 32 as indicated at 45 clear view of the die opening 23 and the punch 21 is permitted over a greater area of the article to be cut. This enables the user of the punch more accurately to punch the desired hole since he is able better to align the punch with the cutting die. These and other advantages of the invention will be apparent from the description thereof intended to teach those skilled in the art the manner in which same may be used and practised. It is contemplated that minor changes in the construction described by way of compliance with the patent laws may be had without departing from the scope of the invention as set forth in the claims hereto appended.

What it is desired to secure by Letters Patent of the United States is:

1. In a hand punch having a pair of pivotally connected cross-levers providing a pair of jaws and a pair of handles on opposite ends thereof, one jaw carrying a punch member and the other a cutting die, and a spring member interposed between the handles normally urging the spreading apart of said jaws, a combination stripper and movement limiting member secured between said jaws and comprising an integral stamping formed from an elongate fiat integral strip of resilient metal having an intermediate right-angle step portion thereby forming a fiat rear part and a longer flat offset front part, the fiat rear part being secured to the jaw carrying the die and the front part having a perforate end aligned with the punch member and curved around and forward of the tip of the punch carrying jaw, a free-ended lug struck from the otfset front part at the junction thereof with said step portion and being a planar continuation of said step portion beyond said front part, an integrally bent hook portion on the free end of the lug in the path of spreading movement of said die-carrying jaw for limiting the movement thereof, and a rivet for securing said rear part to said die-carrying jaw, said rivet-being located substantially adjacent said right angle step portion.

2. A structure as claimed in claim 1 in which said handles and their respective jaws have a crossed over channel formation at the pivotal connection thereof and said flat rear part is secured at a single point of attachment and has an extension engaged in said channel formation to prevent lateral rotation of said stripper member.

References Cited in the file of this patent UNITED STATES PATENTS 84,739 Friese Dec. 8, 1868 1,962,193 Heise June 12, 1934 2,120,682 Sharp June 14, 1936 FOREIGN PATENTS 455,839 Great Britain Oct. 28, 1926