SU4526A1 - Fixture for mounting on the propeller shaft of the Reed system - Google Patents

Description

The proposed device is intended to be mounted on the propeller shaft of the Reed system, | made predominantly from a single piece of light metal | with particularly high tear resistance, for example, duralumin- I mini. Solid blades, in the form of I knives, are made so thin that stiffness I is needed during flight, mainly due to the centrifugal force, i while, on the other hand, the cross sections of the blades have such dimensions and shape and so | vary when going from one I section to another, that of a drying ground | stiffness material is sufficient to maintain a constant angle of inclination.

In such screws, some fixtures are made, making it possible to install them instead of wooden screws on the same steel bushings; so, for example, the middle part of the screw may be flattened, or special parts may be left in it, fitted | to commonly used flanges

and bolts bushings. If it were possible to supply such screws with their own sleeves, then their design and weight reduction would be achieved. The implementation of such a device is the task of the present invention, in order to further simplify the construction, reduce the weight of the screw itself and the sleeve, and to obtain the blade of the screw, which develops up to the sleeve itself the same pulling force.

The present invention is intended especially for those cases where it is desirable to manufacture a propeller directly from a sheet of metal obtained by ordinary rolling, without special forging its middle part to obtain the necessary thickening in which the shaft hole is drilled.

To do this, in the middle part of a relatively thin elongated sheet of metal is hollowed out in the middle, which coincides with the plane of the sheet, a slot, which is then distributed by wedging wide

so much so that a sufficiently large hole is formed for the journal of a shaft or a special coupling secured to the shaft by jamming or by other means. The notch has the greatest width in the middle and sharpens towards the blades of the screw, which achieves the rigidity necessary for transmitting the torque; this cutout shape corresponds to a clutch with side projections or ribs, more or less filling the edge, the sharp ends of the cutout with them, and with this increase, the radius of them, the transmission, the cool steepness, the torque. Further, transverse fastenings can be made to securely connect the screw to the engine, preventing further expansion of the cut and damage to the material at its sharp ends.

The present invention causes a particular preparation of metal screws, the structures of which follow from the form of their implementation shown in the drawing, where FIG. 1 is a side view of the screw to be machined; FIG. 2 is a corresponding plan; FIG. 3-plan of the same screw with a ripped middle cut-out, FIG. 4 is a perspective view of a bent screw with an inserted sleeve; FIG. 5,6 and 7 kinds of bushings. respectively, from the side of its larger dimension, from above, and from the side of its smaller dimension, and FIG. 8-middle part of the screw, with reinforcing plates fixed on it, on a larger scale.

FIG. 1 and 2 shows a screw to be processed and consisting of one piece with two blades 2 and 3 and a middle connecting part 4. A screw is made from this sheet of metal by twisting its blades. This screw to be further processed is usually made of a flexible metal with a high tensile strength, for example, of duralumin. in hot condition. The middle part 4 is relatively wide and thin, but it is still the thickest part of the entire screw. In the middle of part 4, a cutout 5 is made, extending across its entire width and coinciding with its plane, with the cutout extending in both directions towards the blades, and the axis of rotation is located in or parallel to this plane. The cut is made as narrow as the tools used for this allow, after which it is distributed to the sides with the help of appropriate wedges until its width reaches the required value; the width is reduced at the ends of the notch toward the blade m and comes down to-no. In this case, the cut-out takes the form of an eye b, convenient for connecting the screw with the engine, where the material does not experience particularly large tensile stresses during wedging, but the length of the screw is reduced, as shown in FIG. 3

Then, the machined screw is twisted in such a way that the blades get the corresponding angles of inclination, decreasing in a helical manner to the ends of the blades, and the twisting is performed evenly along the entire length. The screw is then hot machined.

When twisting, the opposite sharp ends of the extended cut-out b are shifted in mutually opposite oblique directions. The corresponding steel bushing with a hole drilled in the middle 8 (Fig. 6) and a keyway 10, by means of which it is fixed on the shaft pin 9, is provided with opposing outer ribs 11, 11 installed in accordance with the curved cut-out in obliquely against each other, located on a helical surface.

This sleeve is installed in neckline 6 without play; the ribs 11 are provided with bolt holes 12, 12, which are a continuation of the same I holes 13, 13 in the side I walls of the notch. Bolts 14 are fastened through these holes, fastening the hub with the screw, and washers 15 are laid. As fasteners, rigid metal plates 16 located on the outer surface of the middle part of the screw against each other and attached bolts 14. At the same time, they are firmly attached to the side I surfaces of the screw and give greater rigidity to the whole installation. : A reduction in the weight of the sleeve can be achieved by appropriate cuts, drilled holes, and generally remove excess material, and this can be done without reducing its resistance. If desired. instead of the insertion sleeve 7 i, you can fill the hole with an insert, 3 molten or solid:, and in this insert drill a hole for the motor shaft or steel coupling, and from-; The parts are joined at | help track and key. When wedged middle part of screw | must be adapted for

bushings of a certain height, it is possible, as is done in the one shown in FIG. 1, in the form of an embodiment, to the screw being machined, in its middle part, to give a well-defined width; for a sleeve, the height of which is 8 inches, for example, the middle part of the screw, it is this width that is given, while the adjacent parts of the blades can have a greater width, namely 9 or 10 inches.

With the proposed fixture, the screws can be made of rolled metal sheets in the usual way.

The subject of the patent.

A device for mounting on the propeller shaft a Reed system, characterized by the use of a sleeve 7 with oblique side ribs 11 (Fig. 5, b and 7), made according to the shape of the socket 6 in the propeller hub (Fig. 3), and fastened to this hub by means of bolts 14 and strips 16 (Fig. 8), which nest can be formed in the usual way of flashing and cutting a hole in the middle part of the propeller (Fig. 1 and 2),

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