US1144521A - Aerial propeller. - Google Patents

Description

W. S. & A. H. BARROWS.

AERIAL PROPELLER.

APPLICATION FILED MAR.24, 1913.

1,144,521. Patented June 29, 1915.

. TED strains Parana cr me/u.

WILBER S. BARROWS AND ASAHEL H. IBARROWS, 0F CHTCAGO, ILLINOIS.

AERIAL PROIELLER.

Application filed March 24, 1913. Serial No. 756,304.

To all whom it may concern Be it known that we, WILBER S. Barrows and Asnnnr. l-I. BARROWS, citizens of the United States, residing at Chicago, Cook county, Illinois, have invented certain new and useful Improvements in Aerial Propellers, of which the following is a specification. Our invention relates to aerial navigation, and has particular reference to the construction of propellers for aeroplanes.

The object of the invention is to. provide improvements in the propeller to the end of adjusting its pitch, even during flight, to-

the atmospheric conditions and the acquired speed of the aeroplane once it is in motion. Another object of the inventionis to provide adjustable aeroplane propeller blades so that propellers arranged tandem may have the pitch of their, respective blades adjusted with respect to the relative air currents that they encounter, and in view of the factthat the rear of a tandem pair of propellers must operate u on a current of air set in motion by the orward propeller of the pair.

Other subsidiary objects of the invention will appear from the detail description of the invention, which consists in the novel construction, combination and arrangement of parts, hereinafter described, illustrated in the accompanying drawing and incorporated in the appended claims.

In the drawing, Figure 1 is'a sideviewpf one of the propeller blades, together w1th its axial mounting and portions of the re mainder of the propeller. Thisview also shows sectionsof the companion bladeson the same shaft for the arrangement shown in Fig. 5.. Fig. 2 is a view taken on a vertical plane at right angles to the vertical plane of Fig. 1 and represents a tandem pair of propellerson the same shaft, as in Fig. 5,v

parts being broken away, and-also the adjusting mechanism to vary the pitch of the blades. 7 Fig. 3 is a section taken substantially on the line 3-3 of Fig. 2. Fig. 4 is a reduced diagrammatic view showing the difference in pitch between the blades of, respectively, a forward and a rear propeller arranged tandem on a single shaft. Fig. 5 is a perspective view showing on a reduced scale a tandem pair of propellers'to beadjusted in accordance with the means provided for such adjustment shown in the larger views. Fig. 6 is a diagrammatic view showing the theoretical eflect upon-the air slot 12 in the sleeve,

of a propeller having blades arranged in the usual way, or extending on true radial lines from their axes of rotation. Fig. 7 is a diagrammatic view representing the relative effect of the present arrangement of propeller blades upon the air-currents encoun and 4 while the blades of the propeller at the opposite end are labeled 5 and 6. Each propeller blade or Wing is mounted to turn on its longitudinal axis and for that.purpose is provided with a journal or socket portion, this portion for the blade 3 being represented as 7 "and that for the blade 4 as 8. The n'opeller having blades 5 and 6 is identically constructed. The journals 7 and 8 are mounted in a pair of parallel sockets in the propeller hub 9 keyed to the shaft 2, and these sockets are arranged on opposite sides of the shaft 2 which disposes the axes of the blades tangentially to the circular path of the propeller, as shown most clearly in Fig. 1. The mechanism for rotating the propeller blades of either one propeller or both of them together is represented by a sleeve slidably mounted on the-shaft 2 and caused to rotate with said shaft by means of a pin or stud 11 which is fixed in and projects at right angles from the shaft into a which permits its slid mg ,movement. In Fig. 2 this sleeve is shown connected with the four blades of the two propellers, but it .is equally adapted for operating the blades of a single propeller by simply disregarding the connections at one of-the ends of said sleeve. On the ends of the sleeve areshrunk, or otherwise suitably secured,-ball-bearings 13, 14, 15 and 16. The bearing-member 14 of the pair of members at one end of the sleeve, is secured to the sleeve and rotateswith it, whileits companion member 13 is stationary. The same is true of the members 15 and 16 where the member 15 rotates with the sleeve and-tho member 16 is stationary. Balls 17, provided with the usual ball-races, are inserted between the respective pairs of bearing-members. The stationary members 13 and 16 areyoked. together, or connected, by a rod 18 which has threaded engagement with apertured and threaded ears 19 and 20 on way as, for instance,

the members 13 and 16, respectively. To the extreme ends of the sleeve 10 are secured two oppositely disposed pairs of ears, the pair at the left end being designated as 2l'and 22 and the pair at the opposite end, of which only one is disclosed in Fig. 2, as 23. 21 and 22 may be regarded as a side elevation of 23, and 23 an end view of 21 and 22, the one pair of ears being arranged at right angles to the other pair. The inner ends of the blades of each propeller are, laterally of their axes or swivel joints in the hub, connected withthe sleeve 10 by means of rods 24 and-25 which are linked to the ears 21 and 22 on the sleeve and ears 26 and 27 on bars or levers such as 26 in Fig. l adjustably secured in any suitable by means of bolts 26 which engage holes 27 which pass through the lever and blade. Referring to the ear or eye 26, by shifting the bolts 26" into different holes 27 26 may be removed farther.

away from the axis of the blade. Thus a given thrust or pull movement in the rod 2% will, .when the lever is lengthened, produce a smaller turning movement in the blade than when the eye 26 is nearer the axis. By means of this adjustment the blades of one propeller may be set at a pitch different from the pitch of the other pro-' peller blades on the same shaft by making the levers 26 longer on the one set of blades than on the other. The connecting-rods themselves are made variable in length by making them in two sections connected by a turn-buckle 28. In Fig. 4 the propeller blades 5 and 6 represent the rear of a tandem pair and are there shown set at a greater pitch. than the pitch of the blades 3 and 4.

29 represents a suitable strap, cord or other connection secured at 30 to the sleeve in motion relative to the machine.

10, leading toa suitable lever or other control (not shown) at the usual operators seat, by means of which the sleeve may be moved to and fro on the shaft to vary the pitch of the blades 3 and t where only one propeller is used, or blades 3 and 4c and 5 and 6 where the propellers are arranged tandemas in the drawing. By changing the inclination or pitch of the propeller blades the speed of the machine may be varied. Again, when the machine is in motion the blades of the propellers, when set at a fixed pitch, do not obtain the same hold upon the air that they do when the machine is standing still. In the one case the blades take hold of a comparatively still atmosphere while in the other the atmosphere is If the pitch of the blades can be changed to adjust themto the change from the relatively still to the relatively moving air, the initial grip,

which must be comparatively powerful to start the machine, may be maintained to a large extent after the machine is under way, or inflight. As the rear blades of a tan' dem pair of propellers must take hold of air in greater motion than that which the forward blades must operate in, by reason of the rearward current set in motion by the forward blades,"the differential adjustment provided by the turnbuckles 28 is provided so as to enable the operator to set the relative pitch of the rear blades accordingly.

With reference to the mounting of the axes of the blades on opposite sides of the axis of-rotation of the propeller as a whole, Figs. 6 and 7 show the theoretical efl'ect of this change from the usual radial arrangementof the blades shown in Fig. 6. In these figures 31 represents parallel arrows or a given direction of current, while 32 and 33 represent radially extending propeller blades and 34 and 35 the tangentially arcurrent direction at an obtuse angle with reference to the axis of the propeller which tends to scoop in or condense the air in front of the propeller instead of dissipating or rarefying the air outwardly, thus giving the tangent blades a firmer body of air to take hold of. 38 in Fig. 6 represents the theoretical greater density of air atthe outer circle of the propellers circle of movement at the expense of air drawn from the center. If, on the other hand, the air is drawn inwardly in the direction of arrows 37 the surrounding air-supply will be'drawn upon to make the air in the path of the propeller denser. 1

The construction of the blades 3 to 6 is shown in the drawing adapted for the use of light metal such as aluminum for the body of the blade, said bddy being strengthened by a rib 39 made oftubing split longitudinally and secured to one side of the blade in any suitable manner. The journal portions 7 and 8 may be projecting undivided portions (or circular instead of semicircular in cross section) of the tubing 39 or stiffening rib. As shown the outer end tions between said levers and said member, nal portion mounted in the journal bearing, means forvarying the lengths of said cona longitudinall adjustable lever mounted nections, and means for varying the length on each rope er blade at right angles to of throw of said levers. its axis 0 rotation on its journal, and means 5 2. The combination with a propeller, of a for swinging said lever to vary the pitch of 20 hub for the blades of said propeller, jourthe blade. nals on said blades, bearings in said hub for In testimony whereof we have hereunto said journals, means for turning said blades 'set our hands in the presence of two subin said bearings, and means for varyin the scribing witnesses.

10 lever connections to varv the extent 0 the a, i

turning movement of saill blades. 3. In a propeller, the combination with i the blades of said ropeller, of a hub having Witnesses: journal bearings t erein, a stifiening rib for MAE C. ALLEN,

,15 each of said blades, said rib having a jour- J. W. BEcKsTRoM.

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