US3095043A

US3095043A - Sliding attachment for boat propeller

Info

Publication number: US3095043A
Application number: US48680A
Authority: US
Inventors: Leo A Heintzelman
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-08-10
Filing date: 1960-08-10
Publication date: 1963-06-25
Anticipated expiration: 1980-06-25

Description

June 25, 1963 1.. A. HEINTZELMAN SLIDING ATTACHMENT FOR BOAT PROPELLER Filed Aug. lb. 1960 Leo A. He/h/ze/man INVENTOR.

BY WW 5M United States Patent 3,095,043 SLIDING ATTACHMENT FOR BDAT PROPELLER Leo A. Heintzelman, Grmdville, Mich. (4990 Burlingame, Wyoming 9, Mich.) Filed Aug. 10, 1960, Ser. No. 48,680 2 Claims. (Cl. 170-16011) The present invention generally relates to an attachment for boat propellers and more particularly to uch an attachment that will slide radially outwardly to increase the surface area of the propeller blade thus maintaining the operation of the propeller at its maximum efiiciency.

It is well known that engines used in propelling boats and especially small boats produce their maximum horsepower at a relatively high rotational speed. Inasmuch as the resistance to rotation of the propeller for the boat is the same at low rotational speeds as it is at high rotational speeds, the engine quite frequently will not reach optimum operating speeds until after an extended period of time. Therefore, the present invention incorporates a structure which will enable the resistance to rotation of the propeller to be relatively low in the initial stages of rotation of the propeller and until the propeller reaches a predetermined speed at which time the attachment of the present invention will be rendered efiective by centrifugal force thus increasing the efiective diameter and surface area of the blades of the propeller thereby increasing the resistance .to rotation and of course propelling the boat in the desired manner. The extending of the attachment is no accomplished until such time as the boat propeller has reached a predetermined speed inasmuch as centrifugal force is relied upon to operate the attachment.

Still another important object of the present invention is to provide an attachment for boat propellers which is in the form of a sliding element spring biased radially inwardly and movable outwardly in response to centrifugal force and including means for guiding the movement of the attachment in relation to the propeller blades.

Still another important object of the present invention is to provide a propeller attachment which will not materially increase the thickness of the propeller blades thus enabling the propeller blades to operate in substantially their normal eflicient manner.

Still another feature of the present invention is to provide an attachment for a boat propeller which is simple in construction, easy to use, effective for its particular purposes and generally inexpensive to manufacture.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully thereafter described and claimed, reference being had to the accompanying drawing forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is an end elevational view of a boat propeller employing the attachment of the present invention thereon;

FIGURE 2 is a detailed sectional view taken substantially upon a plane passing along section line 22 of FIGURE 1 illustrating the details of the attachment;

FIGURE 3 is a detailed sectional view taken substantially upon a plane passing along section line 33 of FIGURE 2 illustrating further details of the spring mechanism for retaining the attachment in place; and

FIGURE 4 is an exploded group fragmental perspective view of the components of the attachment and the manner in which the components are assembled.

Referring now specifically to the drawings, the numeral generally designates a propeller on which the attachment of the present invention is mounted and the attachment is generally designated by the numeral 12. The propeller 10 is of substantially conventional construction and includes a centrally disposed hub 14 for receiving the end 3,095,043 Patented June 25, 1963 of a propeller shaft in the usual manner. Extending outwardly from the hub 14 is a pair of propeller blades 16 of identical construction and the propeller blades are disposed at a desired angle and are of a particular size dependent upon the particular type of motor or engine which will drive the propeller. The construction of the hub and the orientation of the blades 16 is conventional and each blade 16 is provided with a generally curved outer edge 18 Adjacent the outer edge 18 of each 'blade 16 is the attachment 12 which is in the form of substantially an arcuate plate 20 having a rounded outer edge 22 generally conforming to the edge 18. The end edges of the plate 20 are rounded as indicated by the numeral 24 and the inner edge thereof is provided with a concave curvature 26 thereon.

The plate 20 is adapted to move inwardly and outwardly in relation to the blade with one end of the plate 20 generally moving along a radius extending from the center of the hub 14 and the other end of the plate 20 moving in parallel relation thereto.

For mounting the plate 20 slidably on the blade 16, there is provided a pair of

pins

26 and 28 extending through apertures 30 in the blade 16 and retained in position by cotter pins 32 or the like. The other end of the pins '26 and 28 are headed as indicated by the numeral 34.

The

pins

26 and 28 extend through an elongated generally rectangular slot 36 in the plate 20* and the pins are in alignment with each other in the direction of sliding movement of the plate 20.

Overlying the slot or enlarged opening 36 and forming a closure therefor is a retaining plate 38. The

pins

26 and 28 also extend through the retaining plate 3% and retains the plate 38 against the outer surface of the sliding plate 20 for forming a closure for the opening or slot 36 in the sliding plate 20. Thus, the plate 20 is capable of sliding between the blade 16 and the retaining plate 38 and the plate 20 is retained in position by the

pins

26 and 28 extending through the opening 36 which limits the sliding movement of the plate 30.

Means is provided for spring biasing the sliding plate 20 inwardly and this mean includes a flattened spiral coil compression spring 40 having the end edges or portions 42 of the innermost loop received in notches 44 in the side edges of the opening 36. The other end of the spring 40 is provided with a hook 46 for attachment to the outermost pin 26. Thus, as the plate 20 moves outwardly, it will carry the lowermost convolution of the spring 40 with it thus compressing the spring 40 whereby the spring 40 will normally urge the sliding plate 20* back towards the hub 14. The hook 46 is securely fixed to the pin 26 and will cooperate with the spring 40 to exert force on the plate 20 for retaining it in retracted position.

Normally, the extensible plates or blades 20 are in retracted position with the outer edge 22 coincident with the outer edge 18 of the blade 16. This condition will be maintained during initial low speed rotation of the propeller thus enabling the engine which propels the propeller to reach an optimum operating speed. As this optimum speed is approached, the centrifugal force exerted on the plates 20 due to the rotation of speed of the propeller will overcome the tension of the springs 40 and thus compress the springs 40 and the plate 20 will be moved outwardly into the dotted line position illustrated in FIGURES l and 2 thus increasing the efiective surface area of the blades 16 for increasing the resistance to rotation of the propeller and, of course, increasing the thurst on the boat. However, this does not occur until the engine has reached the optimum operating speed thus enabling the engine to obtain its optimum operating speed quicker than with a conventional propeller.

The plate 20 is also provided with an inwardly extending flange 21 that engages the opposite surface of the blade 16 in relation to the plate 20 thereby forming a guide for movement of the plate 20 during movement thereof. The flange 21 also serves to stabilize the extensible plate 20' and retain it in position when in the retracted position.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In combination with a boat propeller having a plurality of generally radially extending blades, an attachment comprising an elongated extensible plate for each blade of the propeller, each of said plates overlying and extending across one face of the outer end portion of the corresponding blade and having a curved outer longitudinal edge portion generally conforming to the plan outline of the outer edge portion of the corresponding blade, means at each of the opposite ends of each plate slidably mounting that end on and exteriorly of the corresponding blade by means of a pin and slot connection for movement generally radially of the corresponding blade and including resilient means connected between portions of said blade and the corresponding plate yieldably urging said plate toward a radially inwardly displaced position relative to the corresponding blade when the propeller is rotated at slow speed and enabling the plate to move radially outwardly when the propeller is rotated at higher speeds, said pin and slot connections on each extension plate including a pair of enlarged openings formed in and disposed adjacent the opposite ends of the plates, retaining means projecting laterally from the one face of each of said blades extending through each opening and anchored to the corresponding propeller blade, a retainer member on the outer ends of each of said anchor means and slidably engaging the corresponding extensible plate thus slidably retaining the extension plate in position, said resilient means interconnecting the anchor means and the extension plates for biasing each of the extension plates radially inwardly of the corresponding blade, said means urging the extension plate inwardly of the propeller blade including a flattened spiral coil spring disposed in each opening and having one end anchored to the extension plate and the other end anchored rigidly in relation to the propeller blade thereby resiliently biasing the extension plate inwardly in relation to the propeller blade.

'2. The combination of claim 1 wherein the innermost convolution of the coil spring is provided with laterally extending members, the edges of the openings in the extension plate having notches therein receiving the edges of the lowermost convolutions of the spring thereby anchoring the spring to the extension plate.

References Cited in the file of this patent UNITED STATES PATENTS 1,569,473 Garcia Jan. 12, 1926 2,021,470 Upson Nov. 9, 1935 2,885,012 Heintzelman May 5, 1959 2,992,686 Heintzelrnan et al July 18, 1961 FOREIGN PATENTS 325,296 Germany Sept. 11, 1920 a 425,914 Great Britain Mar. 25, 1935

Claims

1. IN COMBINATION WITH A BOAT PROPELLER HAVING A PLURALITY OF GENERALLY RADIALLY EXTENDING BLADES, AN ATTACHMENT COMPRISING AN ELONGATED EXTENSIBLE PLATE FOR EACH BLADE OF THE PROPELLER, EACH OF SAID PLATES OVERLYING AND EXTENDING ACROSS ONE FACE OF THE OUTER END PORTION OF THE CORRESPONDING BLADE AND HAVING A CURVED OUTER LONGITUDINAL EDGE PORTION GENERALLY CONFORMING TO THE PLAN OUTLINE OF THE OUTER EDGE PORTION OF THE CORRESPONDING BLADE, MEANS AT EACH OF THE OPPOSITE ENDS OF EACH PLATE SLIDABLY MOUNTING THAT END ON AND EXTERIORLY OF THE CORRESPONDING BLADE BY MEANS OF A PIN AND SLOT CONNECTION FOR MOVEMENT GENERALLY RADIALLY OF THE CORRESPONDING BLADE AND INCLUDING RESILIENT MEANS CONNECTED BETWEEN PORTIONS OF SAID BLADE AND THE CORRESPONDING PLATE YIELDABLY URGING SAID PLATE TOWARD A RADIALLY INWARDLY DISPLACED POSITION RELATIVE TO THE CORRESPONDING BLADE WHEN THE PROPELLER IS ROTATED AT SLOW SPEED AND ENABLING THE PLATE TO MOVE RADIALLY OUTWARDLY WHEN THE PROPELLER IS ROTATED AT HIGHER SPEEDS, SAID PIN AND SLOT CONNECTIONS ON EACH EXTENSION PLATE INCLUDING A PAIR OF ENLARGED OPENINGS FORMED IN AND DISPOSED ADJACENT THE OPPOSITE ENDS OF THE PLATES, RETAINING MEANS PROJECTING LATERALLY FROM THE ONE FACE OF EACH OF SAID