US2214622A

US2214622A - Propeller

Info

Publication number: US2214622A
Application number: US166555A
Authority: US
Inventors: Roger E Lorenzen
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-09-30
Filing date: 1937-09-30
Publication date: 1940-09-10
Anticipated expiration: 1957-09-10

Description

Sept. l0, 1940.

R. E. LORENZEN PROPELLER Filed Sept. C50, 1957 0' ff @t je Patented Sept. 10, 1940 i UNITED STATES PATENT OFFICE 3 Claims.

This invention relates in general to a propeller for use with airplanes, boats, fans and the like, and has more'particularA reference to a propeller with adjustable blades adapted to be easily set at any desired angle with respect to the hub for varying the pitch thereof.

An important object of the invention is in the provision of a propeller made of plastic material and cast in one piece.

A further object of the invention is in the provision of blades which vary their contour from the inner to the outer end so that they can be easily adjusted and set at various different pitches with respect to the hub or holder.

A still further object of the invention is in the provision of an adjustable propeller having blades .adapted to be yieldingly set in any desired position in the hubrprior to the attachment of the hub to its rotating shaft.

A still further object ofthe invention is in the provision of a clamping hub or holder, and for a plurality of blades in which the blades are sparately adjustable to vary their pitch and each y Fig. 1 is a perspective view of a two-bladed` propeller attached to the end of a shaft;

Fig. 2 is a sectional view of the hub or blade holder; t

Fig. 3 is a detail of the attached end of one of the blades;

Fig. 4 is a section taken on the line 4-'4 of Figure 3;

Fig. 5 is a perspective illustrating the method of setting the blades at different pitches;

Fig. 6 is' an enlarged view of one of the blades and the holder showing the pitch mark on the blade; and

Fig. 7 is a plan view of a three-blade holder.

This invention relates particularly to a propeller with adjustable blades at the same or difsmall or model airplanes in which it is desired tov vary the pitch of the propeller blades under different conditions, and for 'motors of different sizes. Howevenadjustable propellers of this type for boats, out-board motors, fans and also for larger aircraft.

It is -contemplated that the separate blades will be made of plastic material such as Bakelite, or other condensate products, which are both light 5 and strong, and for propellers of fixed pitch the t blades and central mounting may be cast or formed integrally of the same material requiring no separate hub. The blades may also be made of wood .or light-Weight material for adjustment, 10 as herein set forth.

Referring now more particularly to the drawing, a two-bladed propeller is shown in Figure 1, having separate blades II) mounted at the ends of a hub or holder comprising two similar parts l5 II which when placed together form opposite semi-circular hubs with transverse attachment bores I2 through which a fastening member I3 .may be inserted for rigidlyattaching the propeller to a shaft I4, or other rotating part.

Each of the blades is formed near its inner end with a straight portion I5 of the uniform size at the extremity of which is a flange I6 preferably rounded atv the outer edges. At the inside of the hub members is a straight portion I 1 at 25 the inner end-of which is a curved groove or depression I8 adapted to receive the portions I5 and I6 respectively of the blade. Longitudinal steel wires I9, or other suitable reinforcing struc- A tures, such as I9, as indicated in Fig. l, may be 30 molded or cast in the blades.

'At the outer extremities ofthe hub sections are grooves 20 for setting spring rings 2l therein. In assembling a propeller, the spring rings are commonly placed on the attachment ends of the 35 blades, the blades will ride in the hub parts Il and the spring rings 2l are slipped up over the ends and into the grooves 20, thereby yieldingly holding the hub halves together and the blades clamped loosely therein.

It is to. be understood that the blades vary in shape or contour throughout the length of the blade. That is, the pitch of the blade is increased from the inner portion outwardly. By providing each blade with separate marks designated A, B, 45 C, D and .the like, which relate. to variations in curvature on the pitch of the blade, the blade itself may be set in its holder by applying to the flat or inner side of the blade an angular setting plate or setting device 22 referred to an adjacent 50 plane surface, or as shown in Fig. 5, the assembled propeller may be referred to rectangular cci-ordinates :ii-z, zl-zf, one of which is provided with special graduation's a, b, 'c, d, etc., referred to the length of the blade from the common axis,

and in order to set a blade at any desired pitch, an angular setting device 22 is placed upon a plane surface inv any desired setting position with one edge to engage the inner face of a blade and by adjusting the blade in its holder it will conform to the contact surface 23 of the setting de-` vice at that position. 'I'hus the position of any blade may be adjusted in its holder corresponding to the pitch desired, and each of the blades may be set correspondingly, or the blades may be given different pitches in the same holder. The holding spring rings 2| permit dierent adjustment of the blades in the holder, and whenv the propeller 'thus set is applied to a shaft for rotating it, the fastening device I3 clamps the holder halves Il tightly against the ends of the blades, holding them iirmly in their set position.

It is also contemplated that a multi-blade holder 25, as shown in Figure 7, consisting of similar upper and lower clamping plates secured together by fastening screws 26 may be employed for lpropellers having more than two blades. The separate blades may be individually adjusted, and clamped in place by the holder. y

In this manner a simple adjustable propeller may be produced, which is capable of easy ad- Justment and variation,v the blades being sep-` arately variable for -adjustment of pitch and being releasably held for firmly clamping them in any position in which they are set prior to their attachment to the shaft or other means by which they are rotated. l

I claim:

1. In an adjustable propeller having blades rotatable in a hub about a longitudinal axis, and the pitch of the blade increasing as'its distance from the` hub of the propeller, the method ofv varying and setting the pitch of the blade which consists in providing the blade on one surface with a series of graduations at various distances from thelhub of the propeller and adapted to be referred to a plane surface upon whichY the propeller is placed, such that an angular setting device may be inserted betweenY the surfaces of the plate and thesurface upon which the pro pellerv is supported at one of the graduations, and the blade rotated about the longitudinal axis to conform Athe surface to the edge ofthe setting device depending upon its position with respect to the pitch marks of the blade on the setting surface.

2. Ank adjustable propeller having blades mounted to turn about a longitudinal axis in a hub, the pitch of each ,blade varying as its distance from the hub, and having graduations on the blade indicating distance from the hub; and an angular setting device having one surface to engage a reference surface adjacent the blade and another surface to engage the surface of the blade at various distances from the hub in accordance with the graduations for setting the pitch of the blades.

3. An adjustable propeller having separate blades, a hub having separable plates in which the blades are rotatable about longitudinal axes,

- desired pitch, and means for rmly clamping the hub plates together to hold the blades as set.