US3785052A

US3785052A - Heavy duty nibbler

Info

Publication number: US3785052A
Application number: US00266805A
Authority: US
Inventors: I Yermis
Original assignee: FENWAY MACHINE CO
Current assignee: FENWAY MACHINE CO
Priority date: 1972-06-27
Filing date: 1972-06-27
Publication date: 1974-01-15
Anticipated expiration: 1991-01-15

Abstract

A heavy duty nibbler possessing certain improvements over the nibbler tools of U. S. Pat. Nos. 2,888,744, 2,967,355 and others, including a punch that is threadedly seated in a main body part such that it is not necessary to remove any parts when the punch is threadedly withdrawn from the bottom of the main body part. The punch is of half-moon shape so that the punch makes an initial partial cut into the work. The portions of the punch are angularly related such that the punch is divided into an extending leg having a flattened edge and a main stem with an inclined edge, the angle between the flattened edge and the inclined edge lying between 81* and 83*. The heavy duty nibbler tool further includes a bronze guide sleeve that replaces the nosepiece of U. S. Pat. Nos. 2,888,774 and 2,967,355. The bronze guide sleeve will guide the plunger or ram, thereby preventing the punch from running off center. In the present invention the die is provided with ripples to prevent the metal from backing out, and the die holder is provided with a concave surface. Furthermore, the stripper mechanism is adjustable through the addition of stripper plates in 1/16 increments. Thus, the stripper can be adapted for different thicknesses of the work by simply inserting one or more plates in the top of the stripper. Finally, the main driven gear is provided with a series of openings to eliminate backlash.

Description

i Waited States Patent 8 1 Yermis [5 1 HEAVY DUTY NIBBLER [75] Inventor: Israel J. Yermis, Philadelphia, Pa.

[73] Assignee: Fenway Machine Co., Philadelphia,

[22] Filed: June 27,1972

21 Appl.No.:266,805

52 us. (:1. 30/241 [5i] Int. Cl B26b 15/00 [58] Field of Search 30/228, 241, 242, 30/243; 83/395 [56] References Cited UNITED STATES PATENTS 2,696,044 12 1954 Dod egge 30/241 2,329,387 9/1943 Brenning... 30/242 X 2,650,663 9/l953 Wales 83/395 2,567,095 9/l95l Benjamin 30/24] X 2,827,696 3/l958 Yermish 30/228 2,680,292 6/1954 Kaufmann 30/228 Primary ExaminerDonald G. Kelly Assistant Examiner-J. C. Peters Attorney-Caesar, Rivise, Bernstein and Cohen [5 7] ABSTRACT A heavy duty nibbler possessing certain improvements over the nibbler tools of U. S. Pat. Nos. 2,888,744,

[ Jan. 15, 1974 2,967,355 and others, including a punch that is threadedly seated in a main body part such that it is not necessary to remove any parts when the punch is threadedly withdrawn from the bottom of the main body part. The punch is of half-moon shape so that the punch makes an initial partial cut into the work. The portions of the punch are angularly related such that the punch is divided into an extending leg having a flattened edge and a main stem with an inclined edge, the angle between the flattened edge and the inclined edge lying between 81 and 83.

The heavy duty nibbler tool further includes a bronze guide sleeve that replaces the nosepiece of U. S. Pat. Nos. 2,888,774 and 2,967,355. The bronze guide sleeve will guide the plunger or ram, thereby preventing the punch from running off center.

In the present invention the die is provided with ripples to prevent the metal from backing out, and the die holder is provided with a concave surface.

Finally, the main driven gear is provided with a series of openings to eliminate backlash.

10 Claims, 5 Drawing Figures magnum 15 um 3.785.052

SHEET 10? 3 PA'IENTEDJAM 15 am SHEEF 30? 3 tool and more particularly to a new and improved de-- vice of this general class. The present invention constitutes an improvement over U.S. Pat. Nos. 2,888,744,

2,967,355 and others.

Nibbler tools have been gradually improved during the last twenty years as exemplified by U.S. Pat. Nos.

2,827,696, 2,844,872, 2,888,744 and 2,967,355.

- The devices of theforegoing patents have generally involved means to reciprocate a punchholding ram, the ram possessing a central opening to receive apunch shank, a die plate carried by a guide and a stripper. Heretofore, the punch was dropped into the bore of the ram and then held in place by threaded bushings, as

shown in U.S. Pat. No. 2,967,355. This not only made the seating of the punch a somewhat intricate operation. but greatly complicated the removal and replacement of the punch.

Furthermore, the nosepiece of the prior devices was relatively expensive to manufacture, but was necessary to the proper operation of the nibbler tool.

Such prior devices were equipped with dies which, sometimes, allowed the metal to back out, and the die holders of such devices possessed a generally straight edge as distinguished from the concave surface of the present invention.

The stripper mechanism in such devices was not adjustable and so was forced to act on varying thicknesses of the work. Finally, the gear train of the prior devices was comprised of a solid main gear and this led to backlash.

It is a principal object of the present invention to overcome the shortcomings of the prior art by providing a heavy duty nibbler which comprises a threadedly adjustable punch that is inserted upwardly into a threaded opening in the main body part.

Yet another object of the present invention is to eliminate the nosepiece of the prior devices and to instead provide a bronze guide sleeve for guidance of the ram or plunger to prevent the punch from running off center.

Still another object of the present invention is to provide a heavy duty nibbler tool of reasonable cost which can cut faster than prior tools and act upon thicker work pieces.

Still another object of the present invention is to provide a die with ripples to keep the work from backing out and to provide a die holder with a concave surface.

Yet another object of the present invention is to provide a heavy duty nibbler tool with a stripper mechanism that is adjustable to accommodate varying thicknesses of work and which possesses a main gear having openings to prevent backlash.

Other objects and many of the attendant advantages of the invention will be more readily understood by ref-,

erence to the following figures of the drawings wherein:

FIG. 1 is a side elevational view of the heavy duty nibbler of the present invention with certain outer portions removed in order to show various operative elements of the present invention;

FIG. 2 is an enlarged sectional view taking along the lines 2-2 of FIG. 1;

FIG. 3 is an enlarged sectional view taken along the lines 3--3 of FIG. 1;

'FIG. 4 is.a three-dimensional exploded view showing the plunger or ram and a punch about to be threadedly engaged in thebore of the plunger or ram; and

FIG. 5 is a three-dimensionalexploded view showing the stripper mechanism, a stripper plate for adjustment purposes, the die and the die holder.

Referring now in greater detail to the various figures of the drawing wherein like reference characters refer to like parts, there is generally shown at 10 in FIG. 1 a heavy duty nibbler constituting an embodiment of the present-invention.

The heavy duty nibbler 10 is provided with a body 11, a head l2 that is mounted upon the body 11 in axial extension t hereof with the nose of the prior devices having been eliminated and replaced with a bronze guide sleeve 13 (FIG. 1).

The body 11 houses an electric motor (not shown) that is supplied with power through the medium of a cable 14, the electric motor being controlled by the operator through finger pressure applied to a switch control lever 15 that is mounted upon a handle 16. Note also head handle 16A (FIG. 1).

The body 11 and the head 12 are internally provided with means, presently to be described, for translating the rotary motion of the electric motor into reciprocating motion of a punch generally designated 18 (FIGS. 1 and 4), the latter being operatively mounted in a punch holder 20 that is actuated in a down and upstroke by ram 22.

The means for translating rotary motion of the electric motor into reciprocating motion of the punch 18 comprises a generally cylindrical plunger or ram 22 that is provided with a main body part or stem (FIG. 2). Extending transversely through the main body part of the ram 22 (FIG. 2) is a rectangular opening 24 that is defined by horizontally extending upper and lower walls designated respectively 26 and 28 and vertically extending opposite end walls designated respectively 30 and 32. As can be seen in FIG. 4, the punch holder 20 may be an integral part of the ram 22.

As can be best seen in FIG. 4, the punch 18 is of halfmoon shape so that it is effectively divided into extending leg 34 with flattened edge 36 and main stem 38 with inclined edge 40. As can be seen in FIG. 1, the flattened edge 36 is essentially a straight cut whereas the inclined edge 40 is not quite perpendicular to the flattened edge 36. The preferred angle between the flattened edge 36 and the inclined edge 40 lies between 81 and 83. If the angle drops to about then inclined edge 40 points too directly into the work and achieves too much of a bite. On the other hand, if the angle between the flattened edge 36 and the inclined edge 40 opens up to 84 or more, there is an undesirable pushing action.

It can also be seen from FIG. 4 that the punch holder 20 has a central threaded bore 42 as well as a threaded side opening 44 for reception of set screw 46. Also seen in FIG. 4 is access opening 48 in upper wall 26 of ram 22.

From the foregoing it can be seen that the punch 18 is simply threaded into place with the threads 18-A formed on the upper shank of the punch 18 being received in the central threaded bore 42. Once the punch has been threadedly inserted to the approximate desired depth, it is a simple matter to insert a tool through access opening 48 in order to grasp the upper edge of the punch 18 and rotate it to a desired level. Then, a

set screw 50 (which-had been preinserted) can be tightened as well as side set screw 46 through access opening 52 (FIG. 1).

It will be seen that the bronze guide sleeve 13 completely replaces the nosepiece of the prior devices. The bronze guide sleeve 13 guides the ram 22 in its downward and upward stroke and prevents the punch 18 from running off center.

The means for translating rotary motion of the electric motor into reciprocating motion of the punch 18 additionally comprises a pair of ball bearing units designated 56-56 respectively mounted in the transversely extending casing walls 58 and 60 (FIG. 1). Journalled in these units are concentric opposite end portions, respectively designated 62 and 63, of a shaft that is projected through the ram 22. I

The intermediate portion of shaft 64 (with concentric opposite end portions 62 and 63) is eccentrically disposed relative to the opposite

end shaft portions

58 and 60 and is revolvably extended through a central aperture 66 (FIG. 2) formed in a slide block 68 which is mounted in the ram 22 for shifting movement from side to side within the rectangular opening 24. The shaft portion 63 is operatively connected with the electric motor through the medium of a gear train designated generally by the numeral 70 (FIG. 1).

In the operation of the tool, the eccentric shaft rotates in the concentric bearing units 56-56, about its principal axis and the intermediate eccentric shaft portion 64 rotates therewith for reciprocating as a unit the assembly, including the slide block 68, ram 22 and punch 18. It will be observed that the eccentric shaft is adequately supported at both ends thereof in the bearing units 56-56 mounted respectively in the

casing walls

58 and 60 on opposite sides of ram 22.

As can be seen in FIG. I, the main shaft 72 from the electric motor (not shown) meshes with a gear 74 which in turn 'meshes with a larger gear 76 of the gear train 70. Concentric end 63 of the shaft 64 is in turn rotated by the larger gear 76. This relationship is shown in more detail in FIG. 3 wherein the concentric shaft 78 of the smaller gear 74 is actually a spur gear that meshes with the larger gear 76 which possesses gear teeth 80.

It is to be noted that the larger gear 76 is fitted with five transverse holes 82 for the purpose of eliminating backlash or kick.

Attention is now called to FIG. which shows the stripper mechanism 90 as well as die holder 92 positioned below the stripper mechanism 90 as shown in FIG. 1.

The stripper mechanism 90 possesses a body 96 and there is a connecting web 98 that connects the stripper mechanism 90 and the die holder 92. There are four bolt holes 100 in the body 96 that allow the passage of bolts for attachment to the head l2.

Also formed in the stripper mechanism 90 is a hole 102 that allows the passage of punch 18 on its downward and upward strokes. With further reference to FIG. 5, it will be seen that a lug 104 is provided having legs 106 that extend upwardly as well as an arcuate edge 108 formed adjacent one end of the lug 104. There is additionally an arcuate space between the legs 106.

From FIG. 5 it can be seen that the lug 104 is received against the stripper mechanism 90 with the legs I06 extending into an appropriate slot in the stripper mechanism 90 and held in place by the clamping action of end plate 1 18 and bolt 120 that passes into the arcuate space 110 that is then received in an appropriate opening in the stripper mechanism 90.

The stripper mechanism may be rendered adjustable to accommodate different thicknesses of metal with the provision of one or more stripper plates 112 that are basically of a rectangular shape but have a slot 114 and an arcuate edge 116 that generally coincides with the arcuate edge 108 of the lug 104. One or more stripper plates may be interposed between the lug 104 and the stripper mechanism 90 thereby enabling the stripper mechanism 90 to handle work of different thickness, with more plates used with thinner workpieces.

The die holder 92 possesses openings 122 to receive bolts (not shown) to secure the die holder 92 to the punch guide 54.

The die holder 92 further includes a slot 124 for receiving the punch 18 on its downward stroke. A recessed surface 126 is provided for receipt of the die plate 128 which possesses ripples 130 to keep metal removed from the work from backing out. The die plate 128 also includes a slot 132 that coincides with slot I24 to allow passage of the punch 18 on its downward stroke. Finally, a front plate 134 is provided and secured by appropriate bolts.

It is therefore seen that the present invention provides a highly satisfactory heavy duty nibbler. The reciprocal plunger or ram possesses a punch holder with a threaded bore to receive a punch of novel construction by direct threading. The reciprocal mechanism for driving the punch includes a main gear with a series of openings to eliminate backlash. Also, a bronze guide sleeve is provided so that the heavy duty nibbler does not depend upon a nosepiece for its operation.

Furthermore, the heavy duty nibbler of the present invention includes an adjustable stripper mechanism as well as a die with ripples to keep the metal from backing out.

Without further elaboration, the foregoing will so fully illustrate my invention that others may, by applying current or future knowledge, readily adapt the same for use under various conditions of service.

What is claimed as the invention is:

l. A heavy duty nibbler comprising reciprocating means, an elongated punch having a working end and a threaded shank spaced from the working end, a plunger driven by said reciprocating means and including a punch holder for holding the punch and possessing a threaded bore and an access opening, with the threaded shank of the punch being received in said threaded bore, said access opening providing access to the bore to permit a tool to be inserted therein to expedite the connection or disconnection of the punch from the punch holder.

2. The heavy duty nibbler of claim 1 wherein said reciprocating means include a main gear having openings to eliminate backlash.

-3. The heavy duty nibbler of claim 1 wherein said punch is of half-moon shape at said working end.

4. The heavy duty nibbler of claim 3 wherein said half-moon shape is effectively divided into an extending leg with a flattened edge and a main stem with an inclined edge.

5. The heavy duty nibbler of claim 4 wherein the flattened edge and the inclined edge are related to each other in an angle varying between 81 and 83.

least'one stripper plate that is secured to said stripper mechanism for adjustability purposes.

9. The heavy duty nibbler of claim 1 wherein said access opening is axially aligned with said bore and wherein a set screw is disposed within said threaded bore.

10. The heavy duty nibbler of claim 9 wherein a side set screw is provided in the punch holder to aid in the securement of the punch therein.

Claims

1. A heavy duty nibbler comprising reciprocating means, an elongated punch having a working end and a threaded shank spaced from the working end, a plunger driven by said reciprocating means and including a punch holder for holding the punch and possessing a threaded bore and an access opening, with the threaded shank of the punch being received in said threaded bore, said access opening providing access to the bore to permit a tool to be inserted therein to expedite the connection or disconnection of the punch from the punch holder.

3. The heavy duty nibbler of claim 1 wherein said punch is of half-moon shape at said working end.

5. The heavy duty nibbler of claim 4 wherein the flattened edge and the inclined edge are related to each other in an angle varying between 81* and 83*.

6. The heavy duty nibbler of claim 1 including a bronze guide sleeve that is positioned about said punch holder.

7. The heavy duty nibbler of claim 1 including a die with which said punch acts, said die having ripples to keep metal removed from the workpiece from backing out.

8. The heavy duty nibbler of claim 1 including an adjustable stripper mechanism operating in conjunction with said punch, said stripper mechanism including at least one stripper plate that is secured to said stripper mechanism for adjustability purposes.