US2860594A

US2860594A - Splash deflector

Info

Publication number: US2860594A
Application number: US502710A
Authority: US
Inventors: Elmer C Kiekhaefer
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-04-20
Filing date: 1955-04-20
Publication date: 1958-11-18
Anticipated expiration: 1975-11-18

Description

E. C. KIEKHAEFER Nov. 18, 1958 SPLASH DEF'LECTOR Filed April 20, 1955 2 Sheets-Sheet 1 FML/L INVENTOR El MH? 1 MEKHAEFHP ATTORNEY 1 8 E. CI'KIEKHAEFER 2,360,594

SPLASH DEF'LECTOR Filed April 20, 1955 2 Sheets-Sheet 2 JIVVENTOR. [ZMHP 6, KMKHAEfH? ATTORNEJ United States Patent SPLASH DEFLECTOR Elmer C. Kiekhaefer, Cedar-burg, Wis. Application April 20, 1955, Serial No. 502,710

3 Claims. (Cl. 11517) This invention relates generally to outboard motors, and more specifically to an improved splash deflector for an outboard motor.

Outboard motors are generally provided with an exhaust discharge port disposed at the lower end of the drive shaft housing above the water level to eliminate any objectionable exhaust back pressure caused by the water, particularly in reverse operation, which would tend to reduce the engine operating efficiency. The discharge of the exhaust into the atmosphere during engine operation produces undesirable noise and exhaust odors.

Furthermore, splash deflectors of the type embodied in Kiekhaefer Patent No. 2,442,728 have been used to eliminate operational difliculty and unpleasant boating conditions arising as a result of water spray created by the underwater movement of a part of the outboard motor. Although this splash deflector has accomplished that result and has substantially eliminated the objectionable rooster tail developed at conventional operational speeds, it has not been so effective at high operational speeds of present outboard motors. This rooster tail may be defined as the mass of water and water spray arising above the water surface and thrown backwardly in a direction opposite to the direction of the boat and motor. With the increased motor boat traffic on navigable waters, this rooster tail is objectionable with the water and spray therefrom wetting the occupants and the interior of other nearby boats.

It is therefore an object of the present invention to eliminate the unpleasantness resulting from the rooster tail developed by present day high speed outboard motors.

Another object of the invention is the provision of an improved splash deflector for an outboard motor that muffles the exhaust noise produced thereby.

Another object of the invention is to provide an improved splash deflector for an outboard motor wherein the forces developed by the rooster tail against the deflector are used to raise the rear end of the boat.

Another object of the invention is to provide an improved splash deflector for an outboard motor wherein a reduced pressure area is developed at the exhaust port to reduce the exhaust back pressure of the engine.

Another object of the invention is the provision of an improved splash deflector for an outboard motor for downwardly deflecting the rooster tail developed by the outboard motor and boat, thereby shortening its effective range.

Objects and advantages other than those set forth above will be apparent from the following description when read in connection with the accompanying drawing, in which:

Fig. 1 is a side elevation view of an outboard motor secured to a boat and embodying the invention;

Fig. 2 is an enlarged fragmentary side elevation view partially in section showing the invention;

Fig. 3 is an enlarged fragmentary rear elevation view 2,850,594 Patented Nov. 18, 1958 of a portion of the drive shaft housing showing the invention; and

Fig. 4 is a transverse section view taken on line 44 of Pig. 3.

As shown in the drawings, a preferred embodiment of this invention is illustrated and applied to an outboard motor 1 having a drive shaft housing 2, a cowl 3 mounted on the upper end of the drive shaft housing 2 for enclosing an engine, not shown, and a gear housing 4 mounted to the lower end of the drive shaft housing 2. Attachment means comprising a clamp bracket 6 and a swivel bracket 7 is provided as shown in Fig. 1 for attaching the outboard motor 1 pendantly to the transom 8 of a boat.

The drive shaft housing 2 and the gear housing 4 preferably separate just beneath a horizontal anti-cavitation plate 9 which is cast integrally with the housing 2. The plate 9 is disposed above a propeller 11 and serves to prevent cavitation.

The lower end of the drive shaft housing 2 has a rearwardly extending shoe portion 12 which forms a rearwardly and downwardly extending passageway 13 leading to an exhaust discharge port 14.

An improved splash deflector 16 of applicants invention is mounted on the shoe portion 12 of the drive shaft housing 2 above the water line. This deflector member 16 is preferably cast integrally with the drive shaft housing 2. The deflector 16 further extends circumferentially of the housing 2 in the form of a plate-like flange which may be of substantially the same width and thickness throughout its entirety, and is shown preferably concave downwardly with the trailing edge 17 thereof extending rearwardly and downwardly slightly above and substantially parallel to the exhaust discharge port 14.

The splash deflector 16 should be positioned at a height above the water line where it efficiently catches the upward spray and deflects it downwardly. The actual location may vary depending upon the size of the outboard motor 1 and boat, and should not be so high as to become ineffective for the intended purposes. It is important, however, that the trailing edge 17 of the deflector 16 be positioned above and adjacent to the exhaust. port 14 and to extend rearwardly and downwardly substantially parallel to the direction of the exhaust flow therefrom.

In operation, the water and spray striking the splash deflector 16 forms a substantially solid sheet of water which is deflected downwardly decreasing the size of the rooster tail and effectively covering or blanketing the exhaust port 14 to reduce the exhaust noise. The velocity of this sheet of water further develops a low pressure area at the exhaust port 14 reducing the exhaust back pressure of the engine. The water and spray striking the deflector 16 further imparts a force to the deflector tending to raise the outboard motor 1 and rear portion of the boat out of the water. This is particularly beneficial at high speeds Where the rear end of the boat tends to squat or settle down into the water.

Although but one embodiment has been shown and described, it will be apparent to those skilled in. the art that various changes and modifications of the invention may be made without departing from the spirit of the invention or from the scope of the appended claims.

It is claimed and desired to secure by Letters Patent:

1. In an outboard motor having a substantially vertical drive shaft extending downwardly from the engine to a propeller shaft in the water to drive the propeller, a housing for said shafts having a rearwardly extending shoe portion, said shoe portion forming an exhaust passage extending rearwardly and downwardly to an exhaust port through which the exhaust is discharged rearwardly and downwardly, an anti-caviation plate carried by the lower end of said shoe portion substantially parallel to the water line, and a splash deflector comprising a downwardly curved flange of substantial width carried by said shoe above the water line and spaced from said anti-cavitation plate, said splash deflector having a trailing edge extending rearwardly and downwardly above said exhaust passage and substantially parallel thereto to direct a substantially solid sheet of water in a rearward and downward direction substantially parallel to said exhaust discharge during forward movement of the outboard motor whereby said exhaust discharge is effectively mulfied and the exhaust back pressure of the engine reduced.

2. In an outboard motor having a drive shaft extending downwardly from the engine to a propeller shaft in the water to drive the propeller, a housing for said shafts forming a passage leading to an exhaust port through which the engine exhaust is discharged, an anti-cavitation plate formed on said housing above said propeller and substantially parallel to the water line, and a splash deflector carried by said housing above the water line and spaced from said anti-cavitation plate, said splash deflector being disposed above said exhaust port and forming a part of the exhaust passage leading to the exhaust port and having a trailing edge extending rearwardly and downwardly for directing a substantially solid sheet of water substantially parallel to the exhaust discharge during forward movement of the outboard motor whereby the exhaust discharge is effectively rnuflled and the exhaust back pressure of the engine reduced.

3. In an outboard motor having a substantially vertical drive shaft extending downwardly from the engine to a propeller shaft in the water to drive the propeller, a housing for said shafts having a rearwardly extending shoe portion, said shoe portion forming an exhaust passage extending rearwardly and downwardly to an exhaust port through which the exhaust is discharged rearwardly and downwardly, an anti-cavitation plate carried by the lower end of said shoe portion substantially parallel to the water line, and a splash deflector comprising a downwardly curved flange of substantial width carried by said housing above the water line and spaced from said anticavitation plate and merged with the upper surface of said shoe portion to form a part of said exhaust passage, said splash deflector having a trailing edge extending rearwardly and downwardly above said exhaust passage and substantially parallel thereto to direct a substantially solid sheet of water in a rearward and downward direction substantially parallel to said exhaust discharge during forward movement of the outboard motorwhereby said exhaust discharge effectively minded and the exh'aust back pressure of the engine reduced.

References Cited in the file of this patent UNITED STATES PATENTS