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Publication numberUS3183655 A
Publication typeGrant
Publication dateMay 18, 1965
Filing dateSep 18, 1963
Priority dateSep 18, 1963
Publication numberUS 3183655 A, US 3183655A, US-A-3183655, US3183655 A, US3183655A
InventorsDunlap Henry F, Kern Loyd R
Original AssigneeAtlantic Refining Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Rotary bar-type mower blade having a safety deflector
US 3183655 A
Abstract  available in
Images(3)
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Claims  available in
Description  (OCR text may contain errors)

y 8, 1965 H. F. DUNLAP ETAL 3,183,655

ROTARY BAILTYPE MOWER BLADE HAVING A SAFETY DEFLECTOR Filed Sept. 18, 1963 3 Sheets-Sheet 1 I i I Fig 4 INVENTORS Henry F. Dunlap d R. ern BY Loy K Attorney y 13, 1965 H. F. DUNLAP ETAL 3,183,655

ROTARY BAR-TYPE MOWER BLADE HAVING A SAFETY DEFLECTOR Filed Sept. 18, 1963 3 Sheets-Sheet 2 37 I [29 [g7 I 33 I I I 35' 39 Fig 6 T INVENTORS Henry F. Dunlap BY Loyd R. Kern M Attorney y 1965 H. F. DUNLAP ETAL 3,183,655

ROTARY BAR-TYPE MOWER BLADE HAVING A SAFETY DEFLECTOR Filed Sept. 18, 1963 s Sheets-Sheet s a |2 l I I 53 A) ss 49/; Fig. /0 47 I i INVENTORS Henry F. Dunlap BY Loyd R. Kern Afforney United States Patent 3,183,655 RGTARY BAR-TYPE MGWER BLADE HAVING A SAFETY DEIFLEQIGR Henry F. Dunlap, Dallas, and Loyd R. Kern, Irving, Tern,

assignors to The Atlantic Refining Company, Philadelphia, Pa, a corporation of Pennsylvania Fiied Sept. 18, 1963, Ser. No. 309,827 4 (Iiaiins. (Cl. 56-295) The present invention relates to mowing machines and is a continuation-in-part of copending application Serial No. 264,107, filed March 8, 1963, by the present inven tors, now United States Patent 3,109,275. More particularly, the present invention relates to improved cutters for rotary mowing machines of the type which utilize a flat blade rotating in a horizontal plane about a vertical shaft.

Mowing machines of the rotary type conventionally utilize a flat, substantially rectangular blade with portions of the leading edges of the blade sharpened and the blade rotating about a vertically-disposed shaft. In this type of mower, the blade rotates at an extremely high speed and the combination of this high speed, plus the sharpening of the leading edges of the blade, results in a highly eflicient cutting of grass. However, such mowers have been found to be extremely dangerous, both to the operator and the bystanders, due to the fact that foreign objects lying in the grass are struck by the blade and thrown outwardly with great force and a careless operator will sometimes permit his hand or his foot to become inserted under the mower housing in the vicinity of the rotating ends of the blade.

It is, therefore, an object of the present invention to provide a novel and improved cutter for rotary mowers having a high degree of safety.

A more specific object of the present invention is to provide a novel and improved cutter for rotary mowers having a substantially reduced tendency to cause injury to a part of the operators body which may accidentally come in contact with the rotating ends of the blade.

Another object of the present invention is to provide a novel and improved cutter for rotary mowers having a substantially reduced tendency to cause injury to a part of the operators body which may accidentally come in contact with the rotating ends of the blade and having a substantially reduced tendency to throw small objects, such as wires, outwardly.

till another object of the present invention is to provide an improved cutter for rotary mowers having a substantially reduced tendency to cause injury to a portion of the body of the operator which may accidentally come into contact with the rotating ends of the blade and having a substantially reduced tendency to throw large objects, such as rocks, outwardly.

In accordance with the parent application, it was found that the tendency of a bar-type blade to throw objects outwardly could be substantially reduced by providing extensions on the ends of the blade which have noncutting forward faces and extend outwardly beyond the circle described by rotation of the furthest extremity of the sharpened cutting edges of the blade. Thus, a noncutting extension is provided which will strike foreign objects a glancing blow thereby preventing such objects from being struck a direct blow by the actual cutting edge. This action results in a reduced tendency to throw the object outwardly or to cut it into small fragments and propel the fragments outwardly. In addition, the parent application also provides for the forward projection of the noncutting or blunt extension to act as a material engaging means and prevent small objects, such as wires, from being struck by the blade, sliding along the cutting edge and thence being thrown outwardly. It has now been found, in accordance with the present invention, that, in either of these blades of the parent case, injuries caused by the operator accidentally inserting his hand or foot in the vicinity of the rotating ends of the blade can be substantially reduced by mounting on the outermost ends of the blade, generally perpendicular to the blade, a thin shoe element having a blunt forward end and a maximum vertical dimension greater than the thickness of the blade. A part of the shoe element on the end of the blade is positioned in the same plane as the blade and extends beyond the outer extremities of the cutting edge on that portion of the blade where the shoe element is located. This part of the shoe element is aligned with the cutting edge so that this part of the shoe element sweeps in advance the area to be cut by the cutting edge.

The above and other objects and advantages of the present invention will be apparent from the following detailed description when read in conjunction with the drawings wherein:

FIGURE 1 is a perspective view of the preferred embodiment of the blade of the present invention,

FIGURE 2 is a plan view of the top of the blade of FIGURE 1, Y

FIGURE 3 is an end view, partially in section, taken along the line 33 of FIGURE 2, i 7

FIGURE 4 is an end view taken from the right side of FIGURE 2,

FIGURE 5 is a perspective view of another form of blade made in accordance with the present invention,

FIGURE 6 is a plan view looking at the top of the blade of FIGURE 5, V

FIGURE 7 is an end view, partially in section, taken along the line 77 of FIGURE 6,

FIGURE 8 is an end View taken from the right side of FIGURE 6,

FIGURE 9 is a perspective View of still another form of blade made in accordance with the present invention,

FIGURE 10 is a plan view of the top of the blade of FIGURE 9,

FIGURE 11 is a front view of the blade of FIGURE 10,

FIGURE 12 is an end view, partially in section, of the blade of FIGURE it) taken along line l2l2, and

FIGURE 13 is an end View taken from the right side of FIGURE 10.

Referring now in detail to FIGURES 1 through 4, inclusive, the numeral 1 refers to a hat, bar-type blade having an aperture 3 in its center adapted for mounting on a vertically-disposed shaft of a rotary mower. Blade 1, in its preferred form, is narrower at its center and substantially wider on either end for reasons which will be hereinafter pointed out. A portion of the leading edges, with respect to the direction of rotation of the blade, is sharpened to form cutting edges 5 and 7, respectively. The ends of blade I have formed thereon extensions 9 and 11, respectively, which curve outwardly and rearwardly, with respect to the direction of rotation of blade 1, to form blunt or noncutting extensions, as previously taught in application Serial No. 264,107, now United States Patent No. 3,109,275. Also, as previously set forth in said parent application, noncutting extensions 9 and 11 substantially reduce the tendency of the blade to strike a foreign object a solid blow and propel it outwardly with missile force. This results from the fact that noncutting extensions 9 and I1 strike the object a glancing blow which knocks the object relatively gently downor aside rather than projecting it violently outwardly or cutting it into small fragments which are then propelled violently outwardly. Formed on the rearward or trailing edges of the broadened ends of blade I are upturned fan-type elements I3 and 15, respectively. Fan-type elements 13 and plane of the blade. As shown in the preferred embodiment of the invention, shoes 17 and 19 are the same length as the width of the end of the blade and thus the forward ends of shoes 17 and 19 terminate at substantially the same forward point as cutting edges 5 and 7 and have a 'portion which is in the same plane as the blade and which extends beyond and in line with cutting edges 5 and '7, respectively. Forward portions 21 and 23 of shoes 17 and 19 are preferably rounded or made blunt to prevent the shattering of a foreign object or the like and to provide a smooth forward surface which will reduce the chance of injury should the hand or foot of the operator accidentally come in contact with shoes 1'7 and 1%. The top and bottom edges of shoes 17 and 19 should also be smooth or rounded; and, for that matter, the trailing ends of said shoes may also be rounded in a manner similar to that of forward ends 21 and 23. The shoe elements 17 and 19 have a maximum vertical dimension greater than the thickness of blade 1. It is this broad, vertical dimension which reduces the tendency of the blade to cause serious injury to the hand or foot of the operator which may accidentally come in contact with the ends of the rotating blade. By providing vertically-disposed shoes 17 and 19, the hand or foot of the operator will be struck a glancing blow and pushed from the path of the blade by the outer portion of shoes 17 and 19 rather than being struck by cutting edges 5 and 7 of the present blade or a sharp corner such as that found on a conventional blade. In this preferred form, shoes 17 and 119 are generally rectangular in shape with their ends rounded, as previously pointed out. The shoe may extend entirely above, entirely below, or both above and below (as illustrated) the plane of rotation. The broadest portion or maximum vertical dimension of shoes 17 and 19 is about one-half inch or less. It has been found that, if the vertical dimension of shoes 17 and 19 is too great, the shoes will interfere to some extent with the cutting efficiency ofthe blade, and slightly increase the tendency to throw foreign objects. Thus, the optimum vertical dimension from the point of view of safety and cutting efiiciency is that dimension previously set forth.

Referring now to the modified form of the blade of the present invention as illustrated in FIGURES 5 through i 8, inclusive, the numeral 25 designates a fiat, bar-type blade. Blade 25 may take any particular form and hence be substantially rectangular with squared ends as shown in FIGURE 5. It may also have noncutting extensions as shown in FIGURES 1 through 4, and it may be broadened ends with fan elements as shown in FIGURES 1 through 4. In any event, an aperture 27 is formed in the center of blade 25 for mounting on the vertical shaft of a rotary mower. A portion of the forward edges of blade 25 is sharpened to form cutting edges 29 and 31, respec tively. Mounted on the ends of blade 25, generally perpendicular to blade 25, are shoe elements 33 and 35, respectively. Shoe elements 33 and 35 may take any desired form as previously discussed with relation to FIG- URES 1 through 4, so long as their maximum vertical dimension is greater than the thickness of blade 25 and they have a portion which is in the same plane as. the blade and which extends beyond and in line with cutting edges 29 and 31, respectively. Also, as previously pointed out, the forward ends of shoes 33 and 35 should be rounded to form blunt, forward ends 37 and 39, respectively. However, in addition, blunt forward ends .37 and 39 project forward beyond cutting edges 2% and 31. Thus, in addition to providing safety against a hand or foot being struck by cutting edges wand 31 of the blade 25, the blunt forward ends 37 and 39 of shoes 33 and 35 also act as material engaging extensions. These material engaging extensions, as previously pointed out in parent application Serial No. 264,107, now United States Patent No. 3,109,275, act to prevent small objects, such as wires and the like, from sliding along the forward portion of blade 25 and being thrown outwardly by the rotating blade. The optimum dimensions of shoe elements 33 and 35 are the same as those previously set forth with respect to shoes 17 and 19 of FIGURES 1 through 4 with the exception of the length of these elements.

In accordance with FIGURES 9 through 13, the numeral 41 designates a flat, bar-type blade having an aperture 43 at its center for mounting on the vertical shaft of a rotary mower. A portion of the leading edges of blade 41 issharpened to form cutting edges 45. and 47. Noncutting extensions 49 and 51 are formed on each end of blade 41, which project outwardly and rearwardly beyond the circle described by rotation of the furthest extremities of cutting edges 45 and 47. Mounted on the ends of extension 49 and 51 are shoe elements 53 and 55, respectively. Shoe elements 53 and 55 conform to the outward and rearward curvature of noncutting extensions 4-9 and 51 and have a portion which is in the sameplane as the blade and which extends beyond and in line with cutting edges 45 and 47, respectively. In addition, the vertical plane of the outer surface of the shoe elements is generally concave inwardly withrespect to the center of the blade, to thereby present a rounded exterior surface. The curvature and maximum vertical dimensions of shoe elements 53 and 55 have been exaggerated somewhat for clarity of illustration, and normally saidcurvature and said vertical dimension would not be as extreme as that shown. The forward ends 57 and 59 of shoe elements 53 and 55 are rounded to present blunt forward ends, as in previous instances.

It will be obvious to those skilled in the art that the detailed. description and the drawings'are illustrative only and that numerous modifications of the present invention may be made without departing from the basic concept. For example, while all of the shoe elements have been shown as extending above and below the planes of the various blades, these shoe elements may extend either above or below only (as previously indicated) and still provide substantial protection to they operator; provided, that they are greater in vertical dimension than the thickness of the blade. In like manner, while the shoe elements have been shown in a manner such that they would normally be welded to the ends of the blades, any other appropriate method of forming the shoe elements on the ends of the blade may be practiced. In particular, any of the illustrated forms of the shoe elements may be made as an integral part of the bladeitself by cold or hot working. For example,,bending or forming by appropriate die on a hydraulic press may be practiced as well as swaging to upset the end of the blade. Actually, formation of the shoes as an integral part of the'blade is preferred since this operationcan be carried out as a single step in the formation of the blade itself, and the integrity of the resultant product also eliminates the possibility of the shoes becoming disengaged from the blade during use.

In light of the above, the present invention is to be limited only in accordance with the accompanying claims.

We claim:

1. An improved cutter for rotary mowers adapted to rotate in a substantially horizontal plane about a vertically-disposed shaft comprising a flat, bar-type blade adapted for mounting at its mid-point on said shaft and havingat least a portion of its forward edges, with respect to thedirection of rotation of said blade, formed as cutting edges, and noncutting shoe elements formed on the outermost ends of said blade, generally perpendicular to said blade, said shoe elements having a blunt forward end and having a maximum vertical dimension greater than the thickness of saidblade, a part of each of said shoe elements positioned in said horizontal plane and extending beyond the outer extremities of said cutting edges, said part being aligned with the cutting edge on that portion of said blade where said part is located.

2. An improved cutter in accordance with claim 1 wherein the shoe elements are generally rectangular in shape and have a rounded forward end.

3. An improved cutter in accordance with claim 2 wherein the shoe elements are longer than the width of the blade and extend forward beyond the cutting edges of said blade.

4. An improved cutter in accordance with claim 1 wherein upturned, fan-type elements are formed on the rearward edges of the blade near the ends thereof.

References Cited by the Examiner UNITED STATES PATENTS 3,087,298 4/63 Phillips 56295 3,096,608 7/ 63 Williamson 5 6-295 3,097,469 7/63 Belfiore 56-295 3,109,275 11/63 Dunlap et a1. 5 6295 FOREIGN PATENTS 911,439 11/62 Great Britain.

ANTONIO F. GUIDA, Acting Primary Examiner.

T. GRAHAM CRAVER, Examiner.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3087298 *Aug 19, 1960Apr 30, 1963Phillips Sr Walter JRotary mower blade
US3096608 *Jun 15, 1962Jul 9, 1963Williamson Tom RSafety blade assembly for rotary mowers
US3097469 *Jun 19, 1962Jul 16, 1963 Belfiore
US3109275 *Mar 8, 1963Nov 5, 1963Atlantic Refining CoRotary safety blade
GB911439A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3382653 *Oct 16, 1964May 14, 1968Buigne Frank DePower driven rotary mower
US3452524 *Apr 25, 1966Jul 1, 1969Henry M GuettermanLawn mower with yieldably mounted blade
US3466858 *Oct 15, 1965Sep 16, 1969Outboard Marine CorpLawn mower
US4297831 *Feb 7, 1980Nov 3, 1981Black & Decker Inc.Cutting blade for a rotary lawnmower
US4901509 *Jul 19, 1988Feb 20, 1990Leuz Frederick EMulching attachment for lawn mower
US5056605 *Oct 30, 1990Oct 15, 1991Bond William RMultipurpose cutting means
US5199251 *Dec 19, 1991Apr 6, 1993Snapper Power Equipment Division Of Fuqua Industries, Inc.Mulching blade including multiple cutting edges
US5353581 *Feb 2, 1993Oct 11, 1994Fugua Industries, Inc.Mulching blade including multiple cutting edges
US6301868 *Aug 26, 1999Oct 16, 2001James D. SiplingerVortex reducing mower blade
US6640449Jan 7, 2000Nov 4, 2003Andreas Stihl Ag & Co.Cutting blade for a trimmer
US6986239 *Jun 25, 2004Jan 17, 2006Andrew ComptonLawn mower cutting implement
US7617664 *Sep 9, 2005Nov 17, 2009Fitzpatrick Kevin ERotary cutting blade assembly
US8201639 *Sep 11, 2006Jun 19, 2012John SzurpickiRotary lawn edger tool
DE10303213A1 *Jan 20, 2003Jul 29, 2004Dr. Kern GmbhCutterbar for lawnmower, has support arm with a bore at the center for mounting on the shaft of a drive motor, and measurers behind which corresponding air guiding vanes are respectively formed
EP0032967A1 *Jan 29, 1980Aug 5, 1981Black & Decker Inc.Cutting blade for a rotary lawnmower
WO2000021356A1 *Oct 15, 1999Apr 20, 2000Baron Jackie JeanRemovable cutting tool for plant cutting appliances
WO2000041554A1 *Jan 7, 2000Jul 20, 2000Joachim HoffmannCutting blade for a trimmer
Classifications
U.S. Classification56/295, 56/255
International ClassificationA01D34/73
Cooperative ClassificationA01D34/73
European ClassificationA01D34/73