US3116602A

US3116602A - Hydrojet power unit for boats with power reverse propulsion

Info

Publication number: US3116602A
Application number: US108558A
Authority: US
Inventors: Charles J Dahle
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-05-08
Filing date: 1961-05-08
Publication date: 1964-01-07
Anticipated expiration: 1981-01-07

Description

Jan. 7, 1964 c. J. DAHLE 3,116,602

HYDROJET POWER UNIT FOR BOATS WITH POWER REVERSE PROPULSION Filed May 8, 1961 4 Sheets-Sheet 1 INVENTOR. Charles J Duh le A75 Us.

C. J. DAHLE HYDROJET POWER UNIT FOR BOATS WITH POWER REVERSE PROPULSION Filed May 8. 1961 4 Sheets-Sheet 2 INVENTOR. Char/es J. Dab/e M FW- III-II Jan. 7, 1964 c, DAHLE 3,116,602

HYDROJET POWER UNIT FOR BOATS WITH POWER REVERSE PROPULSION Filed May 8, 1961 4 Sheets-Sheet 3 INVENTOR. Char/es I Dah/e Aizjys.

Jan. 7, 1964 c. J. DAHLE 3,116,602

HYDROJET POWER UNIT FOR BOATS WITH POWER REVERSE PROPULSION Filed May a, 1961 4 Sheets-Sheet 4 NVENTOR.

I Char/es a." Doh/e United States Patent 3,116,602 HYDROJET POWER UNIT FOR BOATS WITH POWER REVERSE PROPULSION Charles J. Dahle, Salmon, Idaho Filed May 8, 1961, Ser. No. 108,558 1 Claim. (Cl. 6035.54)

This invention relates to a hydrojet power unit for boats and includes a reversing power system.

The present invention is an improvement over the propulsion and steering unit described in my co-pending appiication, now Patent No. 3,040,696, granted June 26, 1962, for Propulsion and Steering Unit for Boats. In that application was shown a practical version of a hydrojet unit wherein water was taken in along the keel line of the boat and forcibly ejected in a rearward direction through the transom to provide a driving force for the boat. In this prior application is shown a pair of full circle auger impeller units which are used to drive the water through a cylindrical shell. tion contemplates an improved form of impeller blades to be used in this earlier combination. It also contemplates revision of the fixed guide vanes which limit movement of the water to an axial direction. It further adds a reverse power unit so as to enable the operator of the boat to operate it in a reverse direction and to steer the boat while utilizing this reverse operation.

It is a first object of this invention to provide a novel impeller blade for use in this combination, which blade will better utilize the two stage impeller system desired in this unit. In order to accomplish this object smaller arcuate blades are used in the impeller unit adjacent the water intake than are used in the second stage impeller unit placed rearwardly of the first unit. In this way water is allowed to be pulled past the first unit by the action of the blades in the second impeller unit.

It is another object of the present invention to provide a blade having an improved profile which increases the efiiciency and lessens the turbulence of the water being pulled through the hydrojet unit.

It is another object of this invention to provide a reversible power unit adapted to be mounted on the hydrojet unit so as to enable the operator to reverse the direction of the exhausted water so as to drive the boat in a reverse direction.

Another object of the invention is to provide such a reversing drive which can be operated by a single control lever. The controls for the reverse drive further includes steering controls linked with the normal boat steering mechanism. The steering of the boat in reverse drive is thus identical to the operation involved in normally steering the boat in a forward direction.

These and further objects will be obvious from a study of the following disclosure which illustrates a preferred improved form of the invention. It is to be understood that this form is merely exemplary and illustrates the invention while not limiting or defining it. The invention is to be restricted only by the disclosure of the claim which follows.

In the drawings,

The present inven- 3,116,602 Patented Jan. 7, 1964 FIGURE 7 is a side elevational view of the boat seen in FIGURE 1;

FIGURE 8 is a sectional view through an impeller blade taken along line 8-8 in FIGURE 3;

FIGURE 9 is another sectional view through an impeller blade as seen along line 9-9 in FIGURE 3;

FIGURE 10 is a projected view along an arcuate line shown as 10-10 in FIGURE 3 and designed to show the relative curvatures of the blade surfaces;

FIGURE 11 is a fragmentary top view of the reversing unit as seen in FIGURE 1 with the unit in position for reverse drive of the boat;

FIGURE 12 is a view similar to FIGURE 11 with the drive control in a neutral position; and

FIGURE 13 is a fragmentary top view of the rudder and reversing assembly, showing the steering control utilized in reverse drive.

This invention relates to several improvements formulated with regard to the propulsion unit shown and described in detail in my above cited pending application. The basic operation of the unit remains identical to that described in this earlier description. Many parts of the unit remain unchanged and will not be described in further detail herein. The present invention reflects improvements in the impeller blades, in the guide vanes, in the tail bearing structure and in the directional control for the unit. In the last instance, a totally new reversing mechanism has been added to the unit which was previously only usable in a forward direction.

Referring now to FIGURES 1, 2, 6 and 7, the general scheme of the unit will be described. The propulsion unit is shown mounted upon a boat hull 10, including the bottom 11, adjacent sides 12 and the vertical rear transom 13. The propulsion unit itself is mounted within a cylin drical metal housing 14 which is positioned in a longitudinal direction along the keel of the boat. Mounted at the rear of the cylindrical housing 14 and forming a part thereof is a nozzle section 15. The nozzle section 15 is suitably fastened to the main body of the housing 14 and protrudes through a sealed aperture cut through the transom 13 so as to extend beyond the normal length of boat hull 10. At the forward end of the housing 14 is mounted a grill box 16, identical to that previously shown in my co-pending application. The grill box 16 is adapted to be secured from the exterior of the boat and is sealed within an aperture cut through the bottom 11. The box 16 is hydraulically opened to the forward section of the housing 14 and is suitably fastened thereto. Thus water drawn through the grill box 16 can be passed through the housing 14, including the nozzle section 15, and can be ejected through the open rear end of the nozzle section 15 to thereby propel the boat hull 10 in a forward direction.

Rotatably mounted within the housing 14 is an axial impeller shaft 17. The shaft 17 extends forwardly beyond the housing 14 and may be suitably driven by a con- FIGURE 1 is a top view of the rear section of a boat ventional motor equipped with or without a clutch or transmission, as may be desired. The shaft 17 is rotatably journalled by front bearings .18 which are exteriorly mounted on the front end of the housing 14. The bearings 18 are sealed from the interior of the housing 14 by a suitable packing gland 20. Mounted at the opening from the grill box 16 and fixed relative to the impeller shaft 17 are two blades 21 which form the first impeller unit. These blades 21 are formed on a hub 22 which is suitably keyed to the shaft 17 so as to rotate as a unit therewith. The blades 21 are spiral auger blades, each of which transcribes an arc having a total arcuate distance of less than degrees. These blades can be seen in FIGURE 3. Thus water can be drawn between the two blades 21, although the majority of water area encountered by blades 21 will be axially pushed thereby. Mounted directly rearward of the first blades 21 are a pair of second blades 23 which form the second impeller unit. The blades 23 are formed on a hub 24 which also is suitably keyed to the shaft 17. The are circumscribed by each of the blades 23 is greater than that circumscribed by the blades 21. This may be seen in FIG- URE 4. Each of the blades 23 is almost 180 degrees about the center of shaft 17 so that substantially all the water area encountered by blades 23 is axially moved along the longitudinal direction of the cylindrical housing 14.

Interposed between the blades 21 and the blades 23 is a first stationary guide vane unit. The guide vanes 25 are formed within an outer ring 25a and an inner ring 25b. The two rings 25a and 25b are split so as to be positioned about the shaft 17. The outer ring 25a is secured to the housing 14 by any suitable means such as welding or releasable bolts. Mounted directly rearward of the second blades 23 is a second set of guides 26. The guide vanes 26 extend in a radial manner similar to the guide vanes 25. The final guide vanes 26 are bounded by an outer ring 26a and an inner ring 26b, within which the tail bearings 28 are housed. The tail bearings 28 are mounted within a sealed grease housing 27 which tapers rearwardly so as to lessen water turbulence. The tail bearings 28 serve to rotatably position the rear end of the impeller shaft 17 and to accurately position the two sets of

blades

21 and 23 within the housing 14.

.The contour of the

blades

21 and 23 is extremely important. These blades contours must be formed so as to minimize avater turbulence while providing an effective axial push on the volume of water transmitted through the housing 14. In order to accomplish these results the blade contours are formed as shown in FIGURES 8 through 10. Each

blade

21 or 23 has a vertical rear surface 21a or 23a. This surface is spiralled about the axis of shaft 17 to the desired arcuate extremes. Each blade 21-23 also includes a tapered forward surface 21b or 23b. These surfaces are tapered outwardly from the hubs 22 or 24 to form a relatively thin outer radial edge adjacent the interior surface of the housing 14. The thickness of the blades 2 1-23 also decreases arcuately from their arcuate centers to their outer radial edges. This can be seen in FIGURE 10' which illustrates the fact that the forward surface 21b of a blade 21 has a greater convexity relative to the concavity of the rear surface 21a. Thus the blades 2123 are formed with thick central hub areas which taper both radially and arcu-ately to their extreme edges which are formed in a quite thin fashion. This blade form reduces turbulence in the water by providing a relatively thin meeting edge which extends to a strengthened middle blade area for maximum strength, while also serving further to compress water pushed by the

rotating blades

21 and 23.

The fact that the first blades 21 are less long circumferentially than the second blades 23 provides additional thrust in the unit as a whole. The blades 23 can thus draw the water past the first blades 21 to thereby add to the total thrust exerted on escaping water ejected through the nozzle section 15. Thus both blades 21 and both blades 23 are fully utilized to move a total volume of water through the interior of the housing 14. This actually reduces the incidence of vacuum pockets forming within the housing 14 and reduces turbulence throughout the entire unit.

Normal forward steering of this unit is provided by a rudder 30 which extends partially within the nozzle section 15. The rudder 30 is fixed to a rudder post 31 rotatably journalled on the nozzle section 15. The post 3-1 is moved by means of a crank arm 29 and by a control cable 32 which is suitably moved from the interior of the boat hull 10. In forward operation the rudder 30 is maintained in a straight longitudinal position as shown in FIGURE 1. To turn the boat in either direction the cable 32 is moved to pivot the rudder post 31 and thereby block a portion of the nozzle section 15 and deflect the remaining water volume ejected through the housing 14 and nozzle section 15. This portion of the steering arrangement is identical to that described in my co-pending application. 1

Since the instant unit is designed primarily for use in rivers and shallow locations where a low total draft is desirable, the maneuverability of the boat hull 10 is further enhanced by the provision of a reversing mechanism. .Il'l order to accomplish this result the instant unit is shown provided with a perpendicular tube 33 fixed to the forward end of the nozzle section 15 and open thereto. The tube 33 is formed integrally with a pair of forward projecting extensions 34 and 35 which open to

apertures

36 and 37 sealed through the sides 12 of the boat on either side adjacent the housing 14. Thus water ejected through the tube 33 will be directed outwardly to the

apertures

36 and 37 in a susbtantially forward direction to thereby propel the boat hull 10 in a rearward direction.

The control of Water flow through the nozzle section '15 and tube 33 is governed by three vertical butterfly valves. A central large valve 38 is mounted in the nozzle section .15 directly rearward of the opening of tube 33 to the nozzle section 15. The valve 38 is fixed to a pivot shaft 40 which in turn is suitably journalled for rotation about a vertical axis by the nozzle section 15. The two sides of tube 33 are selectively sealed by

side valves

41, 42, which are respectively fixed on

pivot shafts

43, 44 which in turn are rotatably mounted by the tube 33 for rotation about vertical axes. Thus closing of the

valves

41, 42 will prevent entry of water into the tube 33, while closing of the valve 38 will prevent the issuance of water through the nozzle section 15.

:In order to interrelate the positions of these three

valves

38, 41 and 42, a combined control system is provided. The pivot shaft 40 is provided with a crank arm 45 at the top end thereof and the two

pivot shafts

43 and 44 are respectively provided with crank

arms

46 and 47. These three

arms

45, 46 and 47 are pivotally joined by a common connecting link 50. The connecting link 50 can thus rotate all three

valves

38, 41 and 42 simultaneously. An operating arm 48 is fixed to the crank arm 46 and provides the necessary leverage for remote movement of the three

pivot shafts

40, 43 and 44. The arm 48 is moved by a suitable operating rod 51 which is connected to its outer end. The operating rod 51 extends forwardly along the boat hull 10 to any suitable conventional mechanism adapted to reciprocate it in a longitudinal direction. Any common lever system would .be suitable. The rod 51 is shown in 'FIGURE 1 in its forward position with the valve 38 wide open and the two

side valves

41 and 42 completely closed. Thus the total volume of water moved through the housing 14 will be ejected through the nozzle section 15. At the opposite extreme is the condition shown in FIGURE 11 wherein valve 38 has been closed and

valves

41 and 42 have been opened by rearward movement of the rod 51. in this condition no water will be ejected through the nozzle section 15 and the total water volume will be ejected through the

side apertures

36 and 37. Between these two extreme positions the rod 51 may be positioned as desired so as to modulate the boats speed or to provide a neutral condition by partially opening all three

valves

38, 41 and 42. Such a neutral position is illustrated in FIGURE 12, with the rod 51 in a position intermediate that shown in FIGURE 1 or 11.

In order to further add to the maneuverability of a boat equipped with this propulsion unit, reverse steering has been provided in the illustrated embodiment. This steering is accomplished by a pair of

side steering valves

52 and 53, positioned adjacent the

side valves

41 and 42 respectively within the tube 33. The

valves

52 and 53 are identical in structure to the

valves

41 and 42 and are fixed to pivot

shafts

54 and 55 respectively. The

shafts

54 and 55 are capped by two crank

arms

56 and 57. The two arms 56 and '57 are biased against stops 62 and 63 by tension springs 58 and 60 respectively. The remaining ends of the springs 58 and 60 are fastened to the top center of the housing 14. The stops 62 and 63 are fixed to the outer surface of the tube 33. Thus the springs 58 and 60 maintain the two

steering valves

52 and 53 in a normally fully open position. The two crank

arms

56 and 57 are connected to the rear end of the rudder arm 29 by means of a cable 61 which is threaded through the transom 13 and guided by pulleys 64. As can be seen in FIGURE 13 the

valves

52 and 53 are operated in conjunction with the rudder 30 by the control cable 32. In FIGURE 13 the control cable 32 is shown in a position which would normally direct the boat to the right in a forward direction in the absence of the reverse propulsion means described above. With the valve 38 opened and the boat being projected in a forward direction the

valves

52 and 53 would operate but would be of no importance since no water would be flowing past the

side valves

41 and 42. If the

valves

41 and 42 are opened, as when the boat is being driven in a reverse direction, movement of the rudder 30 will close one of the

valves

52 or 53 and thereby restrict the flow of water through one of the extensions 34 or 35. This will propel the boat to one side or the other. The direction of travel will be opposite to that attained during forward drive. However, the turning moment exerted on the boat hull will be the same so that movement of the boat will not be resisted by the rudder 30. The

valves

52 and 53 will operate in conjunction with the rudder 30 to provide a total steering control during intermediate positioning of the rod 51 between the neutral position shown in FIGURE 12 and the two extreme positions shown in FIGURES 1 and 11.

Thus the improved hydrojet unit described in the above specification provides a more eflicient impeller mechanism at a lower cost due to the savings in materials over a full 360 degree arbor blade. It also provides a greater efliciency and load distribution between the two impeller units. It reduces turbulence and increases the volume capacity of the impeller units. The hydrojet unit also embodies a workable reversing drive, utilizing a simple mechanism to great advantage. The reversing mechanism shown is particularly well adapted for the hydrojet unit as described and combines therewith to provide a fully maneuverable power and steering unit. Various modifications may occur to one skilled in this field without deviating from the basic concepts described above. For this reason the invention is to be limited only by the following claim.

Having thus described my invention, I claim:

In a propulsion unit for boats having a cylindrical housing mounted on the boat hull with a water inlet formed through the hull in connection with the forward end of said housing, said housing including a rear nozzle extending through the boat transom, and impeller means mounted within said housing:

a reversing mechanism, comprising:

a pair of hollow tubes opening to said housing rearward of said impeller means and forward of the nozzle opening, each of said tubes extending transversely from said housing and terminating in a forwardly directed opening formed through the boat hull above the water line adjacent said housing and at each side thereof;

a first butterfly valve located Within said housing rearwardly of the openings of said tubes to said housing, said first valve being adapted to selectively prevent flow of water through said nozzle;

second and third butterfly valves located respectively within said pair of tubes adjacent said housing, said second and third valves being adapted to selectively prevent flow of water through said tubes;

a manual control linking said first, second and third valves adapted to simultaneously operate said valves to selectively open said first valve and close said second and third valves or to close said first valve and open said second and third valves, or to attain an intermediate setting of the three valves between these two extreme conditions;

fourth and fifth butterfly valves located respectively within said pair of tubes;

and control means linking said fourth and fifth valves to the boat steering controls whereby operation of the steering controls will selectively restrict flow of water through one of said pair of tubes and increase flow through the remaining tube.

References Cited in the file of this patent UNITED STATES PATENTS 340,237 Nagel et al. Apr. 20, 1886 514,527 Wauters Feb. 13, 1894 849,030 Valliquette Apr. 2, 1907 2,024,274 Campini Dec. 17, 1935 2,706,451 Mayer-Ortiz et a1 Apr. 19, 1955 2,944,393 Fox July 12, 1960 2,993,463 McKinney July 25, 1961 3,078,661 Spence Feb. 26, 1963 OTHER REFERENCES Robberson: Water-Jet Propulsion, Yachting Magazine, November 1959, pp. -71 (vol. 106, No. 5).