US3183655A

US3183655A - Rotary bar-type mower blade having a safety deflector

Info

Publication number: US3183655A
Application number: US309827A
Authority: US
Inventors: Henry F Dunlap; Loyd R Kern
Original assignee: Atlantic Refining Co
Current assignee: Atlantic Richfield Co
Priority date: 1963-09-18
Filing date: 1963-09-18
Publication date: 1965-05-18
Anticipated expiration: 1982-05-18

Description

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.

Claims

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 HAVING AT LEAST A PORTION OF ITS FORWARD EDGES, WITH RESPECT TO THE DIRECTION 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