US 3740848 A
Description (OCR text may contain errors)
Fleming 83/469 United States Patent [1 1 1111 3,740,848 Lindley June 26, 1973 ROTARY CUTTER ASSEMBLY 3,263,538 8/1966 Gobel et al. 83/629 x 1,165,022 12/1915 Rice 30/319 X [761 Invent Lmqky, 1464 3,496,817 2/1970 Staats et al. 83/614 x Oakland, Calif. 91604  Filed: Aug. 16, 1971 Primary Examiner-Andrew R. Juhasz Assistant ExaminerW. D. Bray  Appl' 172069 Attorney-Edward Brosler  U.S. Cl 30/319, 83/469, 8834/6612?  ABSTRACT 51 1m. 01.... B26b 3/00 A cutter for Sheet material such as sheet metal. lino- 58] Field of Search 30/319, 320, 321, m 919-, wherein a rotary cutting blade is p 30/276; 83/614, 627, 629, 469, 633, 635 Cally actuated by means of a handle terminating in a gear sector or pinion which engages a slidably sup- 5 References Cited ported rack, which in turn controls the reciprocal movement of the rotary Cutting blade. 2,875,828 3/1959 6 Claims, 4 Drawing Figures ROTARY CUTTER ASSEMBLY My invention relates to cutting tools and more particularly to a tool for cutting material such as sheet metal, linoleum and the like.
Among the objects of my invention are:
To provide a novel and improved rotary cutter assembly for cutting sheet material such as sheet metal, linoleum and the like;
To provide a novel and improved manually operated tool assembly which can be operated with a minimum of effort to produce powerful cutting forces for the cutting of sheet material;
To provide a novel and improved manually operative cutting tool assembly for sheet metal and the like, which will provide a smooth non-jagged edge;
To'provide a novel and improved manually operable sheet metal cutter employing a rotary cutting blade.
Additional objects of my invention will be brought out in the following description of a preferred embodiment of the same, taken in conjunction with the accompanying drawings, wherein FIG. 1 is a plan view of my novel and improved sheet metal rotary cutter assembly, with the handle removed to more clearly depict certain details;
FIG. ll is a view in side elevation of the rotary cutter assembly of FIG. I, with the handle in position to initiate a cutting stroke of the rotary blade;
FIG. lll isa view comparable to FIG. 11, but showing the handle in the position occupied upon the completion of a cutting stroke; and
FIG. IV is a view in section, taken in the plane 4 4 of FIG. 1.
Referring to the drawings for details of my invention in its preferred form, the same comprises a base'l in the form of a plate, which functions as a support for all the components involved. Cutting is accomplished through the use of a rotary cutting wheel 3 which is supported for limited translatory movement with respect to the base. The means for mounting said cutting wheel involves a cutting wheel holder 5 in the form of a channel shaped bar 7 which is provided at one end with means for rotatably mounting the cutting wheel in a manner to permit of its exposure below the'lower edges of the channel bar for cutting purposes.-
At spaced locations on the channel bar, the channel bar is provided with a lateral flange, 9 and 11 respectively, the two flanges being interconnected by a rack 13 paralleling the channel bar to form a unitary assembly.
This unitary assembly is slideably mounted in a pair of spaced guides 15 and 17 respectively, located along a longitudinal edge of the base and designed to slidably receive the flanges 9 and 11 so as to permit sliding movement of the unitary assembly which supports the rotary cutting wheel.
To accomplish this, each of the guides is of rigid sheet metal, following the contour of the channel bar and flange, and itself terminating in a flange 19 for riveting or bolting of the same to the base. Actually, each guide may be formed from an integral lateral extension of the base plate, by bending the extension at the edge of the base plate and then contouring it to the channel bar 7 and its integral flange 9.
As thus far described, the unitary assembly including the rack 13 is adapted for sliding movement on the base plate. Such movement in the embodiment illustrated, is
manually controlled by a handle 21 terminating in a gear sector or pinion 23 meshing with the rack. The handle is pivotally mounted between two angle supports 25, 27, each anchored to the base plate, to one side of the rack, the rack responding to a downward movement of the handle to urge the channel bar forward to effect a cutting stroke of the cutting wheel.
Returned movement of the channel bar to place the wheel in position for another cutting stroke, can be effected by lifting the handle, but I prefer to accomplish the return stroke automatically. This can be readily accomplished by providing an abutment 29 at the outer end of the forward guide 17 and installing a compression spring 31 within this guide, between the abutment and the forward end of the channel bar 7, whereby, upon initiating a forward stroke of the cutting wheel, the spring will be compressed, and upon release of pressure upon the handle, the spring will restore the channel bar and cutting wheel, as well as the handle, to its initial position, ready for the next cutting stroke.
By shifting the assembly after each cutting stroke relative to the work, to bring the cutting wheel up to the end of the preceding cut, a substantial length of sheet metal may be severed, and unlike the jagged cut normally made with the use of tin snips or the like, the cut resulting from the use of the present invention, will be continuous and smooth.
It is desirable in a tool of this type, to provide for replacement and interchangeability of cutting wheels. Further, I have found that in cutting material of differ ent thicknesses and other characteristics, that more effective cutting may be accomplished by imposing a degree of resistance to the rotation of the cutting wheel.
With all this in mind, adjustable braking means is provided which, at the same time, can be manipulated to permit removal and replacement of the cutting wheel, as and when desired. v
Accordingly, the cutting wheel 3 is provided with a fixed shaft 35, of a length approximately the distance between the sidewalls of the channel bar 7, which on one sidewall, at the location of the cutting wheel, is provided with a hollow internally threaded boss 37 to receive a thumb screw 39 having an axial shaft receiving recess 41 in its far end. I
The cutting wheel, with a lock washer 45 assembled on one end of its shaft, is positioned between the sidewalls of the channel bar, with that end of its shaft in a recess 47 provided on the wall opposite the boss. With a brake disc 49 assembled onto the other end of the cutting wheel shaft, the thumb screw is threaded into the boss to receive the opposite end of the cutting wheel shaft, to support the same for rotation.
The extent to which the thumb screw is threaded into the boss will determine the braking effect of the braking disc against the cutting wheel, and as previously indicated, the effectiveness of the cutting wheel will vary with the thickness and other characteristics of the material being cut.
Should it be desired to remove the cutting wheel for sharpening or replacement, it will be apparent that this can be accomplished by reversing the procedure followed in installing the cutting wheel.
The rotary cutting tool as illustrated in the drawings, will function well in the cutting of relatively thin sheet metal. For cutting heavier gauge sheet metal, a heavier and more rugged design would be desired.
A similar tool for cutting sheet material such as linoleum may be utilized, regardless of the material of which the linoleum may be fabricated. For such use, a cutting wheel of larger diameter would preferably be utilized, along with a larger cutting stroke, necessitating a longer rack and a substantially larger gear sector or pinion associated with the handle. The principle underlying the operation of such tool, would not differ from that described above, however.
A modification of the foregoing embodiment may be effected by adding a positive drive to the rotary cutting wheel 3 by extending the rack 13 rearwardly to a point slightly beyond the cutting wheel and driving the cutting wheel from this rack through a pinion on the cutting wheel shaft and meshing with the rack. As the rack moves forewardly during a cutting stroke, the cutting wheel will rotate.
[f the braking feature is to be retained, it may be installed on the opposite wall of the channel bar.
From the foregoing description of the invention in its preferred form, it will be apparent that the same fulfills all the objects of the invention, and while I have illustrated and described the same in its preferred form, it will be apparent that the same may be subject to alteration and modification without departing from the underlying principles involved, and I accordingly do not desire to be limited in my protection to the specific details illustrated and described except as may be necessitated by the appended claims.
l. A rotary cutter assembly for sheet material comprising a base having a flat bottom surface, a cutter wheel, means for supporting said cutter wheel which means are mounted on said base, are relatively movable with respect thereto, and which support said cutter wheel beyond said base with the cutter wheel in a plane perpendicular to said base and with the cutter wheel extending below the bottom surface of said base, and means mounted on said base for axially moving said means for supporting said cutter wheel to provide a cutting stroke.
2. A rotary cutter assembly in accordance with claim 1, characterized by said means supporting said cutter wheel for limited translatory movement as comprising a guide passageway affixed to said base, a cutter wheel holder slidably installed in said passageway and normally extending beyond an end of said passageway to provide an exposed end, and a cutter wheel rotatably affixed to said exposed end.
3. A rotary cutter assembly in accordance with claim 2, characterized by said guide passageway having a spring abutment at the opposite end of said passageway, and a compression spring installed in said passageway between'said abutment and the proximate end of said cutter wheel holder, to restore said cutter wheel holder and cutter wheel to its stroke starting position.
4. A rotary cutter assembly in accordance with claim 3, characterized by said means for moving said cutter wheel to provide a cutting stroke, as comprising a rack slidably mounted on said base for movement in a direction paralleling said passageway, means connecting said rack to said cutter wheel holder for movement of said holder as a unit with said rack, and a handle pivotably mounted at a point above said rack and terminating in a gear sector meshing with said rack.
5. A rotary cutter assembly in accordance with claim 1, characterized by said means for moving said cutter wheel as comprising a rack slidably mounted on said base for movement in a direction paralleling the path of movement of said cutter wheel, means connecting said rack with said cutter wheel supporting means for movement of said supporting means as a unit with said rack, and a handle pivotally mounted at a point above said rack and terminating in a gear sector meshing with said rack.
6. The assembly of claim 1 wherein said means for supporting said cutter wheel includes adjustable braking means for regulating the resistance to rotation of said cutter wheel.