US3826217A - Jet propulsion apparatus for boats - Google Patents

Abstract

A jet propulsion apparatus for boats wherein the inlet is mounted below the hull of the boat so that upon forward movement of the boat a ramming effect is attained which causes an increased volume of water to flow into the apparatus. The apparatus having a duct extending upwardly to an impeller chamber all of whose cross sectional areas displaced by water are equal. A centrifugal pump directs the flow into a second chamber having straightening vanes therein and whose cross sectional area displaced by the water is equal to 0.707 of that of the impeller chamber thereby increasing the velocity of water by a factor of 1.414 through said second chamber and discharged by a discharge nozzle connected thereto with an arcuate deflector member both pivotally and rotationally mounted at the discharge nozzle for steering and reversing the boat.

Description

United States Patent 11 1 1111 3,826,217

Canova [4 July 30, 1974 i [54] JET PROPULSION APPARATUS FOR 57 ABSTRACT BOATS A jet propulsion apparatus for boats wherein the inlet lIWenIOfI Henry Callova, 1575 87th is mounted below the hull of the boat so that upon for- Ave', Miami, 33144 ward movement of the boat a ramming effect is at- [22] Filed: Sept 10, 1973 tained which causes an increased volume of water to flow into the apparatus. The apparatus having a duct PP 1 96,119 extending upwardly to an impeller chamber all of whose cross sectional areas displaced by water are 52 U.S. c1. 115/12 R, 60/221 equal A centrifug? Puml? direcfs 51 1111.121 B63h 11/00 Ond chamber f stralghtfrnmg vanes them" [58] Field of Search 115/11 12 R, 12 A, 13, whose cross secnonal area displaced by the water is 1 15/14 15. 1 14/150 151. 222 equal to Of that Of the impeller chamber thereby increasing the velocity of water by a factor of 1.414

[ 56] References Cited 1 through said second chamber and discharged by a dis- 1 charge nozzle connected thereto with an arcuate de- UNITED STATES PATENTS flector member both pivotally and rotationally Chl'OniC 0| R mounted at the discharge nozzle for teering and re- 3,302,605 2/1967 Kuether 115/12 R versing the boat 3,465,705 9/l969 Castoldi 115/12 R 3,589,325 6/l97l Tattersall ll5/l2 R Primary Examiner-Trygve M. Blix nl'igw'mgpgggg Assistant Examiner.lesus D. Sotelo Attorney, Agent, or Firm-Salvatore G. Militana PAIENIEB JUL30l974 saw 20F a JET PROPULSION APPARATUS FOR BOATS BACKGROUND OF THE INVENTION 1. Field Of The Invention This invention relates directly to jet propulsion apparatus for propelling boats and the like.

2. Description Of The Prior Art It is common knowledge that the jet propulsion devices for boats and the like is less efficient than propeller driven apparatus for the reason of the inherent design of the device. However, the obvious advantages derived from the use of jet propulsion devices have caused an increasing number of boat buyers to prefer the jet propulsion manner of propelling a boat than the more efficient propeller driven boat. The inefficiency of the jet propulsion device that is inherent in the device itself, of course cannot be overcome, but a larger part of this inefficiency is due to improper design of the jet propulsion devices.

Most, if not all of the popular jet propulsion devices have their inlet mounted on the bottom of the boat, flush with the hull. This structure compels the water to be sucked into and lifted up to the centrifugal pump. The efficiency of these devices is naturally reduced since the pump must use some of its power in bringing the water to the pump. In addition, the velocity of the discharged stream of water determines the speed of the boat being driven. No attempt is made to vary the sizes of the inlet portion of the centrifugal pump with that of the outlet portion so that an increased velocity at the discharge portion is effected. With all other factors equal, the jet propulsion device that discharges the water at higher velocities will be the more efflcient device since the reactive forces of the discharge water determines the speed of the boat.

A further characteristic of conventional jet propulsion devices which tends to reduce the efficiency thereof, is the improper design of the deflector members which fail to deflectthe stream of water with as little loss of kinetic energy as possible in the steering of the boat. Some such devices divert the stream of discharged water by blocking off the discharge nozzle when it is desired to move the boat in a rear direction. The present invention contemplates avoiding all of the above indicated objections to the conventional jet propulsion devices and thereby produces a jet propulsion device whose efficiency closely relates to that of the propeller operated devices.

SUMMARY OF THE INVENTION Therefore, a principal object of the present invention is to provide a jet propulsion device for boats and the like having an inlet below the hull of the boat acting as a scoop as the boat moves forwardly to obtain a ram effect that increases the normal intake of water thereby.

Another object of the present invention is to provide a jet propulsion device whose discharge portion thereof is smaller in cross sectional area than that of the intake portion so that since the same volume of water that enters the device must be discharged therefrom, the velocity of the water being discharged by the discharge nozzle will be higher and consequently the speed of the boat will be increased thereby.

A further object of the present invention is to provide a jet propulsion device for boats and the like whose steering and reverse movement device consists of an arcuate deflector plate rotatably about a horizontal axis and pivoted to swing in a vertical plane for steering the boat and for movement of the boat in a rearward direction.

A still further object of the present invention is to provide a jet propulsion device with an arcuate deflector plate that is pivotally mounted on a collar which is itself rotatably mounted on the discharge nozzle so that the deflector 'may be positioned in the path of the discharging stream of water to effect the steering of the boat in a most efficient manner.

With these and other objects in view, the invention will be best understood from a consideration of the following detailed description taken in conjunction with the accompanying drawings forming a part of this speciflcation, with the understanding, however, that the invention is not confined to any strict conformity with the showing of the drawings but may be changed or modified so long as such changes or modifications mark no material departure from the salient features of the invention as expressed in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS In The Drawings:

FIG. 1 is a fragmentary side elevational view of a boat on which is mounted a jet propulsion apparatus constructed in accordance with my invention.

FIG. 2 is a fragmentary rear elevational view thereof.

FIG. 3 is a cross sectional view taken along the line 3-3 of FIG. 2.

FIGS. 4 and 5 are cross sectional views taken along the-lines 44 and 5-5 Respectively of FIG. 3.

FIG. 6 is a fragmentary side elevational view similar to FIG. 1 showing the deflector member of the steering apparatus in section and positioned in a neutral position.

FIG. 7 is a similar view showing the deflector member in reverse.

FIGS. 8 and 9 are top plan and rear fragmentary views showing the deflector member in position for steering the boat to the left.

FIGS. 10 and 1 l are similar views showing the deflector member in position for steering the boat to the right.

Referring to the drawings wherein like numerals are used to designate similar parts throughout the several views, the numeral 10 refers to my jet propulsion apparatus mounted on the stern 31 of a boat 11 and having a water inlet forming a scoop 12 mounted on the undersurface of a hull 23 of the boat 11. The inlet 12 is fitted with a strainer consisting of a plurality of vertically spaced members 13 to prevent foreign matter and the like from entering the inlet 12.

The inlet 12 extending through an opening 24 in the boat hull 23 is connected by a pipe 14 that extends upwardly and connects with a chamber 15 in which a centrifugal pump 16 having a plurality of impeller blades 17 is mounted thereon within a housing 49. The pump 16 is mounted for rotational movement on the end of a shaft 18 which extends through an opening 19 in the pipe 14 and is coupled as at 20 to a shaft of a motor or engine 21 (shown only in part).

The impeller chamber 15 communicates with an outlet chamber 22 in a housing in which there ismounted a plurality of conventional straightening vanes 25 that force the water rushing therethrough to flow in a substantially straight line. The outlet chamber 22 is connected to the outlet or discharge pipe 26 that extends through an opening 30 in the transom 31 of the boat 11 whereby the discharge water effects the desirable reactive force at the discharge outlet 27 to propel the boat 11 in a desirable direction as explained in detail hereinafter. Housings 49 and 50 are fastened together as by bolts 51 and supported on posts 60, 60. It is to be noted that the cross sectional area of the inlet 13, pipe 14 and unoccupied area of the chamber 15 are equal so that the rate of flow of water along the full length thereof is constant. Likewise, the cross sectional area of the nozzle 27 and the unoccupied area of the chamber 22 are equal. However, the cross sectional area of the nozzle 27 is 0.707 of that of the inlet 12 so that as the water is ejected by centrifugal force by the impellers 17 at 45 angle with the axis of rotation and the straightening vanes25 straighten the flow of water in the chamber 22, the velocity of the water at this position and at the outlet 27 of the nozzle 26 is increased by a factor of 1.414. By providing the inlet 12 below the bottom 23 of the boat 11, as the boat moves forwardly in the water, the scooping of water by my apparatus causes a ramming effect which not only increases the volume of flow through my apparatus 10 but also prevents the build-up of any pressure in the chamber thereby increasing the efficiency of my jet prupulsion device 10.

Mounted for rotational movement about the discharge pipe 26 is an elongated collar 32 that extends through the opening 30. The collar 32 is provided with bearing races 33, 34 and thrust bearing 35 to permit the collar 32 to rotate with ease about the pipe 26. The bearings 33 and 35 are supported within housings 37 and 38 secured by bolts 39 extending through the transom 31. A radially extending tab or tiller 36 mounted on the inner end portion of the collar 32 within the boat 11 is connected as at 141 by a cable 40 that extends within a pipe 48 to an operatinglever (not shown) for steering the boat 11. On the outer end of the collar 32 there is a pair of longitudinally extending tabs 41 to which an arcuate deflector member 42 is pivotally mounted as at 43. The deflector member 42 is provided with an actuating arm or lever 44 fastened at one end thereto and having its outer end portion connected as at 45 to a cable 46 for pivoting the deflector in a vertical plane. The cable 46 mounted in a pipe 47 extends through the opening 30 in the transom 31 and is connected to an operating lever (not shown) which in conjunction with the tiller will steer the boat 11 as is explained hereinafter.

In the normal operation of my jet propulsion apparatus 10, the motor 21 is operated to cause the shaft 18 and centrifugal pump 16 to rotate. Water is drawn through the inlet 12, into the pipe 14 and chamber 15 to be ejected into the chamber 22 by the pump 16. The water then flows through the pipe 26 to be ejected at the discharge outlet 27 in a solid jet whose reactive force causes the boat 11 to move in a forward direction with the deflector plate 42 out of the path of the discharged jet of water and positioned as shown by FIG. 3. Now if it is decided to turn the boat 11 to the left, the cable 46 is pushed so as to cause the deflector member 42 to pivot downwardly into the path the jet of water being discharged by the nozzle 27 and the cable 40 is pulled to cause the collar 32 and deflector member 42 to rotate about the pipe 26 to the dotted position to the right as seen in FIG. 4.

If it is desired to turn the boat 11 to the right as it moves forwardly in the water, the deflector member 42 is again made to pivot about the pivotpins 43 in a vertical plane in order to intercept a portion of the jet of water being ejected by the nozzle 27. Then the cable 40 is actuated to push the tab 36 and rotate the collar 32 to the dotted line position shown on the left as seen in FIG. 4. The deflector member 42 assumes the position as shown by FIGS. 10 and 11 to cause the forwardly moving boat 11 to turn to the right. If it is desired to maintain the boat 11 motionless while the jet motor 16 is operating, the deflector member 42 is positioned in the path of the jet of water being ejected by the nozzle 26 and directing the flow of water directly downwardly as shown by FIG. 6.

While the boat 11 is in this motionless position, the stern can be manoevuered from one side to the other by rotating the collar 32 which causes the deflector 42 to rotate about the axis of the discharge pipe 26. If the operator of the boat wishes to move directly astern, he pushes the cable 46 to pivot the deflector member 42 to its downmost position as shown by FIG. 7, the jet of water striking the arcuate plate 42 will be deflected below and forwardly of the boat 11 to cause the boat 11 to move rearwardly. By manipulating the cable 40 to pivot the collar 32 in either rotational direction, the boat 11 can be made to turn in either direction as the boat 11 moved rearwardly.

What I claim as new is and desire to secure by Letters Patent of the United States is:

1. A jet propulsion apparatus for boats and the like comprising a water inlet mounted on the lower surface of the hull of a boat, a duct extending upwardly from said inlet, an impeller chamber connected to said inlet, centrifugal water impeller means mounted in said chamber, power operated means connected to said water impeller means, a second chamber connected to said impeller chamber, straightening vanes mounted in said second chamber, a discharge pipe connected to said second chamber and extending through an opening in the stern of said boat, collar means rotatably mounted on said discharge pipe, and water deflector means pivotally mounted on said collar means adjacent an outlet of said discharge pipe whereby said boat may be steered upon pivotal and rotational movements of said deflector means in the path of water being discharged by said discharge pipe, sajd deflector means having an arcuate deflector plate, tab means extending at substantially right angle alongeach edge of deflector plate and a pivot pin pivotally mounting each of said tab means to one end of said collar permitting said deflector plate to swing in and out of the path of flow of water being discharged at said outlet.

2. The structure as recited in claim 1 taken in combination with second tab means mounted on the other end of said collar and operating means connected to said deflector plate and said second tab means for rotational and pivotal movement of said deflector plate in steering said boat.

Claims (2)

1. A jet propulsion apparatus for boats and the like comprising a water inlet mounted on the lower surface of the hull of a boat, a duct extending upwardly from said inlet, an impeller chamber connected to said inlet, centrifugal water impeller means mounted in said chamber, power operated means connected to said water impeller means, a second chamber connected to said impeller chamber, straightening vanes mounted in said second chamber, a discharge pipe connected to said second chamber and extending through an opening in the stern of said boat, collar means rotatably mounted on said discharge pipe, and water deflector means pivotally mounted on said collar means adjacent an outlet of said discharge pipe whereby said boat may be steered upon pivotal and rotational movements of said deflector means in the path of water being discharged by said discharge pipe, said deflector means having an arcuate deflector plate, tab means extending at substantially right angle along each edge of deflector plate and a pivot pin pivotally mounting each of said tab means to one end of said collar permitting said deflector plate to swing in and out of the path of flow of water being discharged at said outlet.

2. The structure as recited in claim 1 taken in combination with second tab means mounted on the other end of said collar and operating means connected to said deflector plate and said second tab means for rotational and pivotal movement of said deflector plate in steering said boat.

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