US2631370A - Hand-held motor-driven shear - Google Patents

Description

March 17, 1953 Q GRAY 2,631,370

HAND-HELD MOTOR-DRIVEN SHEAR Filed April 28, 195} CHAR ES B GRAY BY 0% I? T TORIVEV Patented Mar. 17, 1953 UNITED STATES PATENT OFFICE 5 Claims.

This invention relates generally to motordriven sheet-metal cutting tools and more particularly to improvements in the construction of hand-held, electrically operated shears of the type shown and described in my prior United States Letters Patent No. 1,922,846 of August 15, 1933, to which reference is made for an understanding of the general features of the tool and of the operation of all parts thereof not specifically described herein.

Among the objects of the present invention is to provide a motor-driven shear which is exceedingly rugged, yet simple in design and construction and which is efliciently operative to quickly and accurately cut sheet metal stock along straight lines as well as along curved lines of very small radii or of irregular configuration.

An important object of the invention is to provide the shear with a novel construction or" demountable anvil which is adapted to be readily secured to and removed from the operating head of the tool and which serves not only as the support for the lower fixed cutting blade of the shear but also as the guide for the upper vertically reciprocable cutting blade which coacts with the fixed blade to shear the stock fed through the tool.

Still another and important general object of the invention is to provide the shear with a work-supporting and guiding plate, otherwise known as an anvil, of such design and construction as to facilitate cutting the stock along curves of exceedingly small radii regardless of whether the curved lines of cut extend clockwise away from the vertical axis of the coacting cutting blades or counter-clockwise about said axis.

A further object of the present invention is to provide an anvil which is of such design and construction and which is so fitted with a lower a stationary cutting blade in the anvil to more securely lock it in place and so prevent unintentional oraccidental displacement thereof relatively to its coacting reciprocating blade; to lessen the strain to which the unsupported end of the anvil is subjected during operation of the 2 tool; to facilitate adjustment of the lower cutting blade as it becomes worn in use; and to generally strengthen and reinforce the unsupported end of the anvil upon which the stationary cutting blade is mounted.

Other objects and advantages of the present invention will appear more fully hereinafter, it being understood that the present invention consists in the combination, construction, location and relative arrangement of parts, all as will be more fully described hereinafter, as is shown in the accompanying drawings and will be pointed out in the appended claims.

In the said accompanying drawings:

Figure 1 is a side elevational view of a shear constructed in accordance with and embodying the principles of the invention;

Figure 2 is a front elevational view of the shear with the operating head thereof shown partly in section;

Figure 3 is a transverse sectional view as taken along the line 3-3 of Figure 1;

Figure 4 is a transverse sectional view as taken along the line -44 of Figure 1;

Figure 5 is a vertical sectional view as taken along the line 55 of Figure 2;

Figure 6 is a bottom plan view of the operating head of the tool as viewed from the line 6-6 of Figure 1; and

Figure 7 is an elevational view showing the demountable anvil separated from the operating head of the tool.

Referring now more particularly to the drawings, it will be observed that the shear of the present invention is of a form and construction adapted to be held conveniently in the hand of the operator, the operating head of the tool, designated generally by the reference numeral H], being secured in any suitable manner to the forward end of the casing II in which is housed an electric motor l2 for driving a main shaft 13 through the intervention of a gear train designated generally by the numeral M. The main drive shaft I3 is provided at its end with an eccentric l5 which operates upon an eccentric crank I 6 to effect vertical reciprocation of a cutter bar I! which is generally of circular cross section and extends downwardly through a tubular guide and bearing sleeve l8 provided at the forward end of the casing l I. The construction of the casing H and the design and disposition of the motor [2 and the gear train l4 therein may be varied as desired, it being merely noted in this connection that the casing I! is preferably provided with a hand-hold l9 which is fitted with a finger-actuated electric switch for controlling the operation of the motor. The tubular guide and bearing sleeve 18 may be formed as an integral depending extension of the gear box portion 2! of the casing II or it may be secured thereto as a separate removable part.

As most clearly appears in Figures 4, 5, and 6, the lower end of the cutter bar IT is notched out at one side thereof, as at 22, to provide a vertically extending channeled seat for a cutting blade 23 having a beveled shearing edge 24 which projects below the open end of the channeled seat 22. This cutting blade 23 is provided in its outer surface with a vertically elongated recess the bottom of which is slotted, as at 25, in registry with a tapped hole 26 formed in the cutter bar IT. A screw 21 disposed with its enlarged head in the recess of the cutting blade and with its shank projecting through the slot 25 and into the tapped hole 26 serves to secure the cutting blade 23 in vertically adjusted position within its channeled seat 22. In order to further secure the cutting blade 23 in position against longitudinal shifting under the impact of each shearing stroke, the upper end of the blade is backed up by a headed screw 28 the shank of which is threaded into the cutter bar H in vertical alinement with the blade 23. It will be apparent by that simple rotation of the screw 28 in one direction or the other, its head 29 may be shifted lengthwise of the channeled seat 22 to provide a suitably located upper abutment for the cutting blade 23, the screw 2'! being then employed to securely lock the blade in its seat with the upper end of the blade in abutment with the head of the backing screw 28. In order to facilitate adjustment of the latter, its head 29 is provided with circumferentially spaced holes 30 for reception of a suitable pin (not shown) employed to rotate the screw as desired.

Adapted for detachable securement to the lower end of the depending tubular guide and bearing sleeve I8 is a combination unit 3! which serves not only as an anvil, or bed-plate for supporting and guiding the work through the shearing head of the tool, but also as a guide for insuring rectilinear reciprocation of the cutter bar I! with its associated cutting blade 23 and as a support for the lower stationary cutting blade 32 with which the reciprocating blade 23 coacts in the shearing operation. 7

It will be noted that the combination unit BI is provided with a central portion in the form of an anvil 3P of generally arcuate shape in top plan, the upper flat surface of this anvil spiralling downward from one end toward the other thereof and the thickness of the anvil 3P being reduced from its outer peripheral edge 33 inwardly toward its inner edge 34. The latter edge follows a curvature of extremely small radius to provide an opening 35 which laterally communicates with an open-ended notch 36 extending lengthwise of the shearing head in the immediate region of the reciprocating cutting blade 23.

Extending upwardly from the elevated end of the spiral anvil 31 is a tubular post 31 which is provided at its upper end with a radially extending flange 38 adapted to be bolted to a complementally formed flange 39 provided at the lower end of the depending guide and bearing sleeve IS. The tubular post 3'! is of the same diameter as that of the sleeve [8 and constitutes a downward extension of the latter when the registering flanges 38 and 39 are bolted as by,

the bolts 39. It will be noted that the tubular post 3! is vertically notched along one side thereof, as at 40, to provide a vertically extending guideway for the reciprocating cutting blade 23, the opposite side edges of which latter respec-- tively engage the corresponding side edges of the guide notch 40 to prevent twisting of the cutting blade angularly with respect to its vertical axis of reciprocation. Thus, the post 3'! of the anvil member unit 3| serves ,not only to mount the latter operatively in position with respect to the reciprocating shearing blade 23, but also to guide the latter for reciprocation along a definite rectilinear line of travel and in a fixed vertical plane offset to the right of the vertical axis of the cutter bar when the tool is viewed as in Figure 2.

Extending downwardly from the depressed end of the spiral anvil 3l is a vertically extending solid post 4| of generally cylindrical shape, the inner side of this post being milled out, as at 42, to provide a vertically elongated seat for the stationary cutting blade 32 already referred to above. The latter blade is similar in construction to that of the upper blade 23 in that it is provided with a beveled shearing edge 43 and with an elongated recess 44 in the body thereof, the base wall of the recess being longitudinally slotted, as at 45. The blade 32 is secured firmly in its seat 42 by means of a bolt 46 the threaded shank of which projects laterally through the post 4| and the slot 45 of the blade for engage ment by a nut 41 seated in the recess 44, It will be apparent that the blade 32 may be adjusted vertically within its seat to the extent permitted by the length of the slot 45. In order to further secure the blade in its adjusted position against vertical displacement under the impact of eachshearing stroke, the bottom end of the blade is preferably backed up by an axially adjustable screw 48 which in turn is locked in place by a laterally extending set screw 49.

It will be noted that when the cutting blades 23 and 32 are respectively mounted in position and adjusted properly in their seats, the shearing edges thereof are so angularly related as to permit free and easy feeding of the sheet material to be out between and through said edges of the blades. Of course, in practice the tool is generally fed into and through the material along prescribed lines of cut, during which operation the sheared edges of the material are respec: tively deflected above and below the anvil 3 so that one portion of the sheared material rests upon the upper surface of the anvil, while the other portion rides beneath the anvil in close contact with its under surface.

In order to provide the operator of the tool with the fullest possible view of the line of shearing, the flanges 3839 of the vertically alined sleeve 18 and post 31 are commonly cut away as at 50-50, along a transverse line substan tially coincident with the plane of vertical reciprocation of the upper cutter blade 23. In operating the tool for shearing material along a prescribed line of cut, the tool may be fed straight through the material for making a straight line out of indefinite length, or it may be turned to the right or to the left to shear the material along irregular or curved lines. When cutting the material along a line curving to the right of the shearing axis, such line of cut may curve from a straight line of infinite radius to a curved line of a radius as small as that of the upper post 31 of the anvil unit. On the other hand,

when the material is cut along a line curving to the left of the shearing axis, the smallness of the radius of such curvature is limited only by the radius of the lower depending post 4! of the anvil unit. Inasmuch as both of the oppositely projecting posts 31 and M are of small external diameter, the material may be sheared in either direction along lines of exceedingly small radii of curvature and with maximum visibility to the operator of the line of cut.

Due to the fact that the lowering depending post ll with its associated cutting blade 32 is of relatively small overall diameter, it becomes possible to insert said post through a small opening formed in the sheet material preliminarily to effecting an inside out in such material. This is an important feature of the present tool, because motor-driven shears prior to the invention have not been constructed to facilitate making inside cuts except in cases where the sheet material is initially provided with an excessively large opening into which the head of the tool may be inserted.

It will be understood, of course, that the present invention is susceptible of various changes and modifications which may be made from time to time without departing from the general principles and real spirit of the invention, and accordingly it is intended to claim the same broadly, as well as specifically, as indicated by the appended claims.

What is claimed as new and useful is:

1. In a hand-held motor-operated shearing tool, a shearing head comprising a pair of relatively movable cutting blades respectively having overlapping shearing edges forming an acute angle therebetween, a vertically reciprocable bar constituting a mounting for one of said blades, a tubular guide sleeve for the upper portion of said reciprocable bar, a tubular extension of said sleeve detachably secured to the latter in embracing relation with respect to the lower portion of said reciprocable bar, said tubular extension being of an overall external diameter substantially equal to that of said guide sleeve, a spiral anvil integral with and springing downwardly and laterally from the lower end of said extension toward a region spaced to one side of and below said lower end of said extension, the marginal edge of the upper part of said anvil being tangential with the external surface of said tubular extension, and a solid post depending from the depressed end of said spiral anvil, said solid post being disposed laterally to one side of and below said tubular extension with the vertical axis of said post and extension in parallel relation, said solid post constituting a mounting for the other one of said cutting blades.

2. In a handheld motor-operated shearing tool, a shearing head comprising a vertically reciprocable cutter bar having a cutting blade operatively mounted upon one face thereof, a tubular guide sleeve embracing the upper portion of said cutter bar and a combination work-supporting anvil and stationary cutter blade carrier detachably carried by said guide sleeve, said combination anvil and blade carrier including a part constitutinga tubular extension of said guide sleeve and a laterally extending part in the form of a spiral platen tapering in cross-section from a relatively thick outer edge toward a thin inner edge, and having an upper surface which inclines from one side of the axis of reciprocation of said cutter bar downwardly, the marginal edge of said upper surface of the platen being tangential to said tubular extension of the combination anvil and blade carrier, the depressed end of said spiral platen being provided with a stationary cutting blade carrier in the form of an integral depending post of relatively small transverse cross-section disposed in laterally offset relation with respect to said reciprocable cutter bar and with its vertical axis paralleling that of said bar.

3. In a shearing tool as defined in claim 2 wherein said last-mentioned depending post is recessed in one vertical face thereof to provide a seat for said stationary cutting blade, and wherein a cutting blade is adjustably positioned in said seat.

4. In a sheairng tool as defined in claim 2 wherein the adjoining ends of said guide sleeve and tubular extension are respectively provided with mating flanges adapted to be bolted together, said flanges being commonly cut away immediately above the shearing zone to provide maximum view of said zone to the operator of the tool.

5. In a shearing tool as defined in claim 2 wherein the tubular extension forming part of said combination anvil and blade carrier is notched in one side thereof to provide a vertically extending guideway for the cutting blade mounted upon said reciprocable cutter bar.

CHARLES E. GRAY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,759,842 Fossa May 27, 1930 2,125,556 Gleich Aug. 2, 1938 2,226,241 Gray Dec. 24, 1940 2,244,638 Boardman June 3, 1941 2,482,582 Grafe Sept. 20, 1949 FOREIGN PATENTS Number Country Date 801,154 France May 16, 1936

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