US2690728A - Weed cutter for outboard motors - Google Patents

Description

.w I I Oct. 5, 1954 H. F. CAVANAUGH WEED CUTTER FOR OUTBOARD MOTORS Filed June 26, 1951 Patented Oct. 5, 1954 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to outboard motors and more particularly to means for cutting weeds in the path of such motors and for improving the steering characteristics thereof.

Many devices are known in the prior art designed to prevent the entanglement of weeds with the motor propeller, but such devices have failed in their purpose with the result that the weeds wind around the propeller shaft, resulting in poor motor operation or stopping of the motor. Such prior art cutter devices as have been designed to cut the weeds have not been practical, inasmuch as they merely cut the weeds in line with the propeller drive shaft, thereby permitting weeds at the sides of the cutter to become entangled with the propeller. Furthermore, most prior art devices of this type have impaired the steering characteristics of the motor.

Accordingly, a primary object of the present invention is to cut the weeds, not only in line with the propeller drive shaft, but also in vertical planes between which the rotational path of the propeller is entirely disposed, to positively prevent the tips of the propeller blades from becoming entangled with the weeds.

A further object of the invention is to devise a cutter device, such as above described, which may be quickly and easily connected to standard outboard motors and which can be adjusted so that the lower ends of the cutters are below the 1ower level of the propeller blades during rotation thereof.

Still another object of the invention is to devise an arrangement in which the cutter may be tilted to increase its cutting efiiciency and may be adjusted fore and aft with respect to the propeller.

A more specific object of the invention is to devise a cutter device wherein at least three parallel blades are provided, one in alignment with the propeller drive shaft, and the others in planes within which the propeller is entirely disposed during rotation thereof.

Yet another object of the invention is to provide means for adjusting the cutter blades relative to each other to increase or decrease the space between the cutting edges thereof by relative fore and aft movement of the blades.

A further object of the invention is to improve the steering characteristics of the motor by providing one or more weed cutters, each in the form of a flat knife-like blade, disposed in a plane parallel or coplanar with the rudder, to function as secondary rudder means in unison therewith.

The foregoing and other objects and advantages of the invention will become apparent from aconsideration of the following specification and the accompanying drawings, wherein Fig. 1 is a perspective view of a conventional outboard motor with a preferred embodiment of the novel cutter device attached thereto;

Fig. 2 is a front elevational view of the novel cutter device shown in Fig. 1;

Fig. 3 is a side elevational view of the cutter device; and

Fig. 4 is a top plan view thereof.

Describing the invention in detail and referring first to Fig. 1, a conventional outboard motor, generally designated 2, comprises a drive shaft housing 4 extending substantially vertically from the under side of a motor casing 6, the lower end of the housing 4 terminating in a conventional gear box 8 containing gear means (not shown) connecting the drive shaft (not shown) within the housing 4 to a propeller I0. A conventional rudder 12 disposed in a substantially vertical plane, is formed on the under side of the gear box 8. The housing 4 is mounted in the usual manner on a boat clamp l3 for rotation relative thereto on a substantially vertical axis to steer the boat.

The novel cutter device, generally designated I4, which may be made of stainless steel or any other desired material, is connected to the housing 4 by means of a pair of clamp straps I 6, arcuately formed to conform to the shape of the housing 4 and interconnected by a bolt and nut assembly 8 to clamp the straps [6 around the housing 4 under sufficient tension to hold the device l4 tightly in position thereon. The device I4 is also supported by one or a pair of pivot links 29, pivotally connected to the rudder 12 by a bolt and nut assembly 22 passing through the links 20 and the rudder I2.

As best seen in Figs. 2 and 4, the cutter device l4 comprises a central blade 24, which is in the form of a thin fiat plate having a cutting edge on its forward surface, as at 26, said edge having rearwardly diverging segments 28 and 30, as best seen in Fig. 3. These diverging segments greatly increase the cutting efficiency of the blade as it passes through vegetation in the water, inasmuch as the divergence of the segments 28 and 30 produces a slicing action, severing weeds against which the blade is forced by the motor 2. The blade 24 is preferably connected to the straps 16 by a bolt and nut assembly 32 passing through an aperture 34 in the blade 24, and said aperture is preferably vertically elongated, as best seen in Fig. 3, to accommodate vertical adjustment of the blade 24 to a position whereat its lower extremity is below the lower level of the rotational path of the propeller l0, whereby weeds are prevented from passing beneath the blade 24 into engagement with the propeller.

Also, as best seen in Fig. 3, the pivot links 20 are connected to the blade 24 by a bolt and nut assembly 36 which extends through a complementary aperture of the blade 24 and through an elongated arcuate slot or aperture in each link 20 to accommodate tilting of the blade 24 by rotation thereof on a substantially horizontal axis about the bolt and nut assembly 34. It may be noted in this connection, that by thus tilting the blade 24, its cutting efiiciency may be increased, by reason of the slicing action imparted to the blade.

The cutter device [4 also preferably comprises a pair of spaced, relatively short, fiat blades 40 and 42 disposed in planes substantially parallel to the plane of the blade 24 and having cutting edges 44 and 46 on the forwardly facing edges thereof, said edges having sloping segments 41 parallel to the segment 30 of the cutting edge 26. The upper ends of the blades 40 and 42 are flanged, as at 48 and 55 respectively, the flanges being provided with bolt and nut assemblies 5| and 52 extending through complementary openings thereof and also extending through horizontally elongated slots 54 and 56 of straps or brackets 53 and 56 secured to opposite sides of the blade 24, as for example, by bolt and nut assemblies 82 or by any other desired securing means, such as rivets or welds.

As best seen in Fig. l, the upper edges of the blades 45 and 42 extend above the upper level of the rotational path of the propeller l0, and the lower ends of these blades preferably extend below the lower level of the rotational path of the propeller. Furthermore, the blades 40 and 42, which, as above noted, are in planes parallel to that of the blade 24, are preferably so arranged that the rotational path of the propeller I is entirely disposed between the planes of the blades 40 and 42, thereby preventing the tips of the propeller blades from extending laterally beyond the blades 45 and 42 and encountering uncut weeds passing therealong.

Another feature of the invention resides in the manner in which the space between the cutting edges of the blades 45 and 42 and the cutting edge of the blade 24 may be increased or decreased by adjustment of the blades 40 and 42 in a fore and aft direction with respect to the blade 24. This is accomplished by loosening the bolt and nut assemblies and 52 and moving the blades 48 and 42 lengthwise of the slots 54 and 56 until the desired spacing between the cutting edges of the blades is obtained, whereupon the bolt and nut assemblies 5| and 52 may be tightened. It will be understood that when the outboard motor 2 is operated in waters containing different types of vegetation, different spacing between the cutting edges 44, 46 and 26 may be desired.

It may also be noted, as best seen in Fig. 1, that the blade 24 is preferably coplanar with the rudder I 2, and the blades 40 and 42 are in planes parallel with respect to that of the rudder l2. Furthermore, all of the blades are preferably in the form of very thin, substantially flat, straps resembling knife blades, to afford minimum resistance against the water when the boat driven by the motor 2 is steered in a straight line. Also, the configuration of these blades is such that extreme sensitivity of steering is achieved, and their form and arrangement accommodates their function as auxiliary rudder means.

In this connection, it may be noted that the brackets 58 and 60 also afford minimum resistance to flow of water therearound, inasmuch as is best seen in Fig. 2, these parts are preferably in the form of thin fiat straps which may, if desired, be formed with cutting edges similar to those of the blades 24, 40 and 42.

The brackets 58 and 60 may be elongated if desired to accommodate additional blades and five or seven or any number of blades may be used as desired and as may be required in waters with heavy vegetation.

It is apparent that the specific illustrations shown above have been given by way of illustration and not by way of limitation and that the structures above described are subject to variation and modification without departing from the scope or intent of the invention, all of which variations and modifications are to be included within the scope of the present invention.

What is claimed as new and desired to be secured by Letters Patent is as follows:

1. A weed cutter device for an outboard motor comprising a substantially flat, vertical blade having a forwardly facing cutting edge, a pair of substantially fiat bracket straps secured to opposite sides of said blade and projecting rearwardly therefrom, a pair of substantially fiat vertical blades having forwardly facing cutting edges, means adjustably securing said pair of blades to the respective bracket straps for adjustment fore and aft with respect to the first-mentioned blade, and spaced means connected to the upper and lower extremities, respectively, of the first-mentioned blade for attaching it to an associated outboard motor.

2. A weed cutter device, according to claim 1, wherein the last-mentioned means comprise a link pivoted to the lower end of the first-mentioned blade, and a clamp having a pin and slot connection to the upper end of the first-mentioned blade to accommodate vertical adjustment thereof with respect to the clamp, said clamp being formed and arranged to embrace an associated drive shaft housing.

3. A weed cutting attachment for outboard motors which comprises a vertically disposed central cutting blade member, a pair of encircling clamp elements for anchoring the upper end of said blade member to an outboard motor vertical shaft housing, a pair of link straps for securing the lower end of the blade member to the shaft housing, a pair of formed sheet metal brackets 'of symmetric and opposite contour having portions bolted to said central cutting blade member, each bracket including a sidewardly offset and rearwardly extending arm containing a longitudinal slot therein, and a pair of side cutter blade members comprising vertical knife blade portions disposed parallelly to said central cutting blade member and having inwardly bent portions adapted to be adjustably secured in the longitudinal slots of said brackets.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,553,182 Mould Sept. 8, 1925 2,054,374 Fuller Sept. 15, 1936 2,140,099 Wise Dec. 13, 1938 2,319,640 Sink May 18, 1943 2,355,842 Arado Aug. 15, 1944 2,468,890 Moore May 3, 1949 2,470,874 Sidney May 24, 1949

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