US931783A - Reciprocating propeller. - Google Patents

Description

B. D. MARKS. RBGIPROGATIN G PROPELLER. APPLICATION FILED SEPT.3. 1908. 93 1 ,783. Patented Aug. 24. 1909. 2 SHEETS-SHEET 1.

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B. D. MARKS. RECIPROCATING PROPELLER.

APPLICATION FILED SEPT. 3, 1908.

\ Patented Aug. 24. 1909.

2 SHEETSSHEET 2.

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Amzw. I. mmuu cu. momma-nus. wmuum n BENNETT D. MARKS, or cIIIcAGo, ILLINOIS.

RECIPROCATING PROPELLER.

Specification of Letters Patent.

Application filed September 3, 1908. Serial No. 451,525.

To all whom-it may concern:

Be it known that I, BENNETT D. MARKS, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois,-have invented certain new and useful Improvements in Reciprocating Propellers; and I do declare the following to be a full, clear, and exact description of the Invention, such as will enable others skilled in the art to-which it appertains to make and use the same.

This invention relates to new and useful improvements in reciprocating propellers for boats.

In constructing. propelles of this type it has beenthe common practice to make the blades in a plurality of hinged sections so that: during the return stroke of the plunger the sections are permitted to fold inwardly in order to reduce the resistance ofiered to their passage through the water to-the greatest possible extent. This form of blade however is decidedly objectionable because of the fact that the blade being made in a number of hinged sections the joints of the sections could not possibly withstand the strain to which they would be subjected, as the plunger makes its thrust and consequently the parts would become deranged or renderedunfit for service after the propeller hasbeen in use but a short period of time.

In order to 'overcomethe above objections, I have devised a propeller which is cast integral or riveted tothe'plunger and have provided guide frames of the desired form whereby the blade is gradually loweredinto the water: as'the plunger makes its thrust andisraisedentirely or nearly clear of the water as the plunger makes its return stroke;

WVith these and other objects in view, the invention consists of certain novel features of construction, combination and arrangement of parts, as will be more fully described: andparticularly pointed out in the appended claims Inthe accompanyingdrawings, Figure 1 is a side elevation of the stern of a boat with my improved form-of propeller applied in position thereto; Fig. 215 a rear view of'Fig. 1 with parts broken away; F1g-. 8 1s a plan view; Fig. 4 a vertical section-taken on the plane indicated by the dotted lines H of Fig.1, looking inthe direction indicated by the arrow.

In the embodiment illustrated the numeral 1 indicates the stern of a boat of any ordinary construction and 2 the improved propelling means which is arranged in the desired position with relation to the stern of the boat. As shown, this propelling means comprises two rigid preferably concavoconvex propeller blades 3 which are arranged at opposite sides of the stern, as shown, and are integral with or rigidly connected to the rear extremities of the pivoted sections 4 of the plungers 5, the latter being connected with a crank shaft 6 extending transversely through the stern of the boat.

Each of the propeller blades 3 is arranged to work between a pair of corresponding laterally spaced guide frames 7 suitably supported in rear of the stern and at the desired height with reference to the water line. Each of these frames is of approxi mately elliptical form and is constructed from a flat piece or bar of metal arranged in edgewise relation with a vertical'plane and provided at opposite side edges with inwardly extending guide flanges 8 to receive suitable rollers 9 journaled to opposite ends of a cross bar 10 one of which is arranged at the rear extremity of the pivoted section of each of the plungers and between each pair of guide frames. By employing a construction of this kind it will be observed that while these frames serve to guide the propeller blades in the desired manner the plungers' are so connected therewith as to reduce friction to a minimum and consequently increase the desirability of the device. These frames comprise lower portions 11 which are gradually curved inwardly in the water and which extend to the rear ends of the frames. The frames are then bent upwardly and forwardly to form upper curved portions 12 of approximately semi circular form, the central portions-of which extend above the surface of the water to the desired distance. By this construction it will be observed that as the plunger makes its thrust its respective blade is gradually lowered into the water until at the rear end of its pair of guide frames and is then raised in approximately edgewise manner until out of the water and returned to initial position.

It is to be further observed that by constructing the lower portions 11 of the guide frames as indicated and described, each of the propeller blades is gradually lowered into the water as its respective plunger makes its thrust and that for this reason the impact is gradual and will not cause severe Patented Aug. 2st, 1909.

shocks or strains to which the boat and propelling means would be otherwise subjected and which would cause the discomfiture of the assengers. It is to be further noted that by lifting the blades out of the water upon the return strokes of the plungers that practically no resistance if any is offered to the return of the propeller blades into initial or normal posit-ion to make the next thrust.

It is to be understood that while the construction of frame which 1 have shown and described is more particularly suited for the purpose than any otner which 1 have been able to devise at the present time, 1 do not limit myself to this particular form of frame but claim the right to use any form or 06nstruction whereby the objects or aims in view heretofore pointed out may be accomplished. It is also evident that the crank arms of the crank shaft are arranged at 180 degrees apart in order that one of the propeller blades will be brought into normal or initial positionwhile the other is making its thrust. Any suitable form of engine may be used to drive the crank shaft.

From the foregoing description, taken in connection with the accompanying drawings, the construction and operation of the invention will be readily understood without requiring a more extended explanation.

Various changes in the form, proportion and the minor details of construction may be resorted to without departing from the principle or sacrificing any of the advantages of the invention, as defined in the appended claims.

Having thus described my invention, what I claim as new is 1. In combination with a plunger, a propeller blade rigidly attached thereto, and guide frames whereby the blade is caused to be gradually lowered into the water during the thrust of its plunger and raised out of the surface of the water upon the return stroke of the plunger.

2. In combination with a boat, a plunger mounted to reciprocate through the stern thereof, a propeller blade made in one piece rigidly connected with the rear extremity of the plunger, and guide frames suitably supported in rear of the stern of the boat whereby the propeller blade is caused to be gradually lowered into the water as the plunger makes its thrust and is raised out of the water during the return stroke of the plunger.

3. In combination with a boat, a plunger mounted to reciprocate through the stern thereof, a concavo-convex propeller blade rigidly connected with the rear extremity of the plunger and a pair of corresponding laterally spaced guide frames for the rear end of the plunger whereby the propeller blade is caused to be gradually lowered into the water as the plunger makes its thrust and is lifted above the surface of the water upon the return stroke of the plunger, and means for driving the plunger.

a. In combination with a boat, a plunger made in two jointed sections mounted to reciprocate through the stern of the boat, a propeller blade made in one piece rigidly connected with the rear extremity of the rear section of the plunger, and means for guiding the rear extremity of the rear plunger section whereby the propeller blade is caused to be gradually lowered into the water as the plunger makes its thrust and is raised out of the water during the return stroke of the plunger.

5. In combination with a boat, a plunger mounted to reciprocate through the stern of the boat a propeller blade cast in one piece rigidly connected with the rear extremity of the plunger, and a pair of corresponding laterally spaced guide frames supported in rear of the stern of the boat and for guiding the rear extremity of the plunger, said frames comprising lower gradually and inwardly curved portions and upper portions of greater curvature, the central portions of the upper portions extending above the water level, and means for driving the plunger.

6. The combination with a boat, of a plunger made in a number of jointed sections mounted to reciprocate through the stern of the boat, a propeller blade made in one piece rigidly connected with the rear extremity of the rear section of the plunger, and a pair of corresponding laterally spaced guide frames supported in rear of the stern of the boat and for guiding the rear extremity of the rear plunger section whereby the propeller blade is caused to be gradually lowered into the water as the plunger makes its thrust and is raised out of the water during the return stroke of the plunger, said frames comprising inwardly extending guide flanges, a cross bar arranged at the rear extremity of the rear plunger section, and rollers j ournaled to opposite ends of the cross bar and adapted to bear between the guide flanges of the frames, and means for operating the plunger.

7. The combination with a boat, of a plunger mounted to reciprocate through the stern thereof, a propeller blade made in one piece rigidly connected with the rear extremity of the plunger, a pair of corresponding laterally spaced guide frames supported in rear of the stern of the boat for guiding the rear extremity of the plunger and where by the propeller blade is caused to be gradually lowered into the water as the plunger makes its thrust and raised out of the water during the return stroke of the plunger, each of the frames being constructed from a flat piece of metal which is arranged in edgewise relation with a vertical plane and is s bent at opposite side edges to form inwardly In testimony whereof I have hereunto set extending guide flanges, a cross piece army hand in presence of two subscribing 10 ranged at the rear extremity of the plunger Witnesses.

and extending between the guide frames,

T and rollers journaled to opposite ends of the BENL ETT MARKS cross piece to bear between the guide flanges lVitnesses:

of the frame, With means for operating the ERNEST H. L. MUMMENHOFF,

plunger. OTTO V. HELLMRICH.

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