US724935A - Propeller. - Google Patents

Description

No. 724,935. PATEN TED APR. 7, 1903.

G. QUICK.

PRO'PELLER. APPLICATION FILED JUNE 28, 1901.

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I UN ITED STATES PAT NT OFFICE.

GEORGE oUIoK, OF B'OURNEMOYUTH, ENGLAND.

PROPELLE-R.

SFEGIFICATION formingpart of Letters Patent N 0. 724,935, dated April 7, 1903.

Application filed nne 28, 1901. Se i l No. 66 ,370. (ModeL) To all whom it may concern.-

Be it known that I, GEORGE QUICK, a subject of the King of Great Britain, and a resident of Bournemouth, England, have invented a new and Improved Propeller, of which the following is a full, clear, and exact description. I

The object of this invention is to form the propelling-surface of the blades so as to reduce the resistance offered to the rotation of the same and at the same time increase the propelling efficiency and decrease the vibration which is generally caused by screws of the ordinary form. This end is attained by forming the propelling-surface of a curve as hereinafter particularly described and so disposing this propelling-surface that it recedes from the hub outward in the direction opposite to that in which the propeller turns in driving the ship ahead, the angle or amount of the said recession diminishing from the root of the blade at the hub outward toward the periphery in the manner hereinafter particularly described. I have discovered that the total amount of the recession of the propelling-surface may with advantage range from forty degrees to eighty degrees, or even more, for propellers for difierent classes of vessels.

This specification is an exact description of my invention, and the claims define the actual scope thereof.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the views.

Figure 1 is a rear end view of a left-handed propeller embodying my invention. Fig. 2 is an elevation of the starboard side of Fig. 1. Fig. 3 is a longitudinal section on the line 3 3 of Fig. 1. Fig. 4 is a partial trans verse section on the line 4 4 of Fig. 2, showing the total recession of the blades in this case to be about fifty-five degrees and that the angle of recession diminishes rapidly from the hub to the end of the blades Fig. 5 is a similar view representing one of. the propellers of the United States late battleship Maine, here illustrated for the purpose of rendering clear the novelty of my inven- .tion.

hub may be of any form desired, and b indicates the blades, which may beattached to the hub in any convenient or desired manner.

In Fig. 1 the arrow 0 indicates the direction in which the propeller is to be-turned-ql. -e., to the left-and therefore 0' in this view indicates the leading edges, and c the following edges, of the blades.

d indicates the propelling-face of the blade, and it will be seen in Figs. 3 and 4; that the propelling-face of each blade is shaped from the hub to the end of each blade as a concave curve, which curve (see Fig. 3) is approximately a portion of a circle whose radius is approximately equal to the diameter of the propeller, (but the exact profile of this curve is not material,) and that the said curved surface (see Fig. 4) recedes from the hub outward toward the end of the blade in the direction opposite to that in which the propeller turns to drive the ship ahead. Fig. 4 also shows that the angle of recession diminishes rapidly from the hub toward the end of the blades.

Referring now particularly to Figs. 4 and 5, the arrows o in both figures indicate the direction in which the propeller turns to drive the ship ahead, and 0 indicates the following edges of the uppermost blades, the rear halves of the said blades being shown in section and the leading halves of said blades having been cut away in the drawings. The radial line a; a: in Fig. 5 and the radial line mm in Fig. 4 are supposed to correspond. Referring to Fig. 5, which shows a type of an ordinary screw-propeller, it will be seen thatthe propelling-surface of the blade, not counting its obliquity due to the pitch, extends practically along the line w m and that it is truly radial from the center of the hub. Fig. 4, illustrating my invention, shows that the propelling-surface d recedes with respect to the line a; at from the hub outward toward the periphery in the direction opposite to that in which the propeller turns to drive the ship ahead, and by referring to the legend Recedes on this View and the figures opposite it, giving the number of degrees of angular recession at the differentradii of the blades, it will be seen that the said recession, measured from the line at w, diminishes rapidly from the root of the blade near the hub outward toward the poriphery. The line 00' 0c in Fig. 4 is so placed in that figure that it will exactly correspond with the line w a; in Fig. 5, this having been done toemphasizethecomparison. However, it is evident if the line x at in Fig. 4 were drawn vertically through the center of the hub the above-described recession would still exist. It is obvious that in connection with this propelling-surface,as described, any kind of pitch may be employed-such as a uniform pitch, a simple increasing pitch, or a simple decreasing pitch-7 e. increasing or decreasing from the leading to the following edge or a progressively-increasing pitch or a progressively-decreasing pitch from the leading edge to the following edge, or a compound increasing pitch or a compound decreasing pitch from the leading edge to the following edge and from the hub outward toward the periphery; but for all ordinary purposes I prefer to employ the blades, as described, having a uniform pitch.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. A screw-propeller, the propelling-surface of the blades of which from the hub outward toward the periphery is in the form of a concave curve, the said curved surface receding from the hub outward in the direction opposite to that in which the propeller turns to drive the ship ahead, and the angle of the said recession of the propelling-surface diminishing from the hub outward to the end of the blade, substantially as herein described.

2. A screw-propeller, the propelling-surface of the blades of which from the hub outward toward the periphery is in the form of a concave curve, the said curve receding from the hub outward in the direction opposite that in which the propeller turns to drive the ship ahead, the angle of recession lying between the range of forty degrees to eighty degrees, and the angle of such recession diminishing from the hub outward to the end of the blades, substantially as described.

In testigpony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

I" GEORGE QUICK.

Witnesses:

J. A. INNEs DUFF, JNo. R. MUMFORD.

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