Folding Propeller

Abstract

The present invention discloses a folding propeller (1) for a boat, e.g. for a sailboat or a multihull yacht, where said folding propeller (1) comprises a hub (2) for directly or indirectly fastening at a driveshaft connected to a motor, where said folding propeller (1) further comprises at least three individual blades (3), where each of said blades (3) comprises a blade root (4) arranged to pivot around a separate pivot pin (9), at said hub (2) in order to be either in a first and operative position, where the blade (3) is pointing mainly in a radial direction, or in a second and inoperative position, where the blade (3) is pointing mainly in an axial direction, where said pivot pin (9) comprises a first and second end (20, 21), where said hub (2) comprises a cut out (19) for each of said blade roots (4), and further comprises a set of holes (10) for installing said pivot pins (9).

Claims

1. A folding propeller for a boat, e.g. for a sailboat or a multihull yacht, where said folding propeller comprises a hub for directly or indirectly fastening at a driveshaft connected to a motor, where said folding propeller further comprises at least three individual blades, where each of said blades comprises a blade root arranged to pivot around a separate pivot pin, at said hub in order to be either in a first and operative position, where the blade is pointing mainly in a radial direction, or in a second and inoperative position, where the blade is pointing mainly in an axial direction, where said pivot pin comprises a first and second end, where said hub comprises a cut out for each of said blade roots, and further comprises a set of holes for installing said pivot pins, where each of the holes in said set of holes for installing the pivot pins are interconnected with an adjacent hole for installation of a separate pivot pin, where two adjacent holes at one end are arranged in a common aperture, called a lockbox seat, where said lockbox seat serves as installation opening for two adjacent pivot pins, wherein the two adjacent installed pivot pins at the respective ends comprise means for engagement with a common lockbox.

2. A folding propeller according to claim 1, wherein said hub is manufactured from a plastic material, e.g. POM, PET, PA, and/or from a fibre reinforced polymer material.

3. A folding propeller according to claim 1, wherein said hub is manufactured from a metal alloy, e.g. bronze or stainless steel.

4. A folding propeller according to claim 1, wherein said lockbox comprises fixating means, where said fixating means are arranged for engagement with at least one of: a lockbox seat, the ends of two adjacent pivot pins, a cross dowel arranged inside of a vertex of the regular triangle or square shaped by the pivot pins when installed.

5. A folding propeller according to claim 1, wherein said lockbox comprises at least one flange, where said at least one flange comprises a hole for engagement with at least one of: a cross dowel and a bolt arranged in parallel with the rotational axis of the hub at the inside of a vertex of the regular triangle or square shaped by the pivot pins when installed.

6. A folding propeller according to claim 1, wherein said lockbox comprises a central and frustoconical hole, where said central and frustoconical hole is arranged to engage a mating frustoconical surface of the ends of two adjacent pivot pins.

7. A folding propeller according to claim 6, wherein said central and frustoconical hole in said lockbox comprises an internal thread, and where said mating frustoconical surface of the ends of two adjacent pivot pins comprises an external thread.

8. A folding propeller according to claim 1, wherein said lockbox comprises an outer frustoconical surface, where said outer frustoconical surface is arranged to engage a mating frustoconical surface in said lockbox seat.

9. A folding propeller according to claim 8, wherein said outer frustoconical surface comprises an external thread, and where said mating frustoconical surface in said lockbox seat comprises an internal thread.

10. A folding propeller according to claim 1, wherein said folding propeller comprises at least one connecting link, where said at least one connecting link comprises means for interacting with at least two of said pivot pins.

11. A folding propeller according to claim 1, wherein said folding propeller comprises at least three individual blades, each blade having a blade root comprising a gear engaging one or more other gears at other blade roots.

Description

DESCRIPTION OF THE DRAWING

[0038] An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0039] FIG. 1 shows a three bladed folding propeller in an operative position;

[0040] FIG. 2 shows a three bladed folding propeller disassembled;

[0041] FIG. 3 shows three pivot pins arranged in a triangle in a first configuration;

[0042] FIG. 4 shows a cross sectional view of a hub;

[0043] FIG. 5 shows a side view of the hub seen in FIG. 4;

[0044] FIG. 6 shows three pivot pins arranged in a triangle in a second configuration;

[0045] FIG. 7 shows a cross sectional view of two pivot pins and a lockbox as seen in FIG. 5;

[0046] FIG. 8 shows three pivot pins arranged in a triangle in a third configuration;

[0047] FIG. 9 shows a cross sectional view of two pivot pins and a lockbox as seen in FIG. 7;

[0048] FIG. 10 shows three pivot pins arranged in a triangle in a fourth configuration;

[0049] FIG. 11 shows a cross sectional drawing of a hub and pivot pins for a three bladed folding propeller, with side links;

[0050] FIG. 12 shows a side link;

[0051] FIG. 13 shows a cross sectional drawing of a hub and pivot pins for a three bladed folding propeller, with a triple link;

[0052] FIG. 14 shows a triple link.

[0053] In the following text, the figures will be described one by one and the different parts and positions seen in the figures will be numbered with the same numbers in the different figures. Not all parts and positions indicated in a specific figure will necessarily be discussed together with that figure.

POSITION NUMBER LIST

[0054] 1. Folding propeller [0055] 2. Hub [0056] 3. Blade [0057] 4. Blade root [0058] 5. Anode [0059] 6. Hub end cap [0060] 7. Lockbox [0061] 8. Gear at blade root [0062] 9. Pivot pin [0063] 10. Hole in hub for pivot pin [0064] 11. Vertex of the pivot pin triangle [0065] 12. Cross dowel [0066] 13. Threaded hole in cross dowel [0067] 14. Locking screw [0068] 15. Hole for cross dowel [0069] 16. Lockbox seat/common aperture [0070] 17. Hole in lockbox flange [0071] 18. Flange at lockbox [0072] 19. Cut out in hub for propeller blade roots [0073] 20. First end of pivot pin [0074] 21. Second end of pivot pin [0075] 22. Engagement means at pivot pins [0076] 23. Surface at pivot pin ends [0077] 24. Internal surface of lockbox [0078] 25. Central hole in lockbox [0079] 26. Threads [0080] 27. Hole in end of pivot pin [0081] 28. Angle [0082] 29. Outer surface on lockbox [0083] 30. Surface in lockbox seat [0084] 31. Bolt [0085] 32. Side link [0086] 33. Holes in the link for the pivot pins [0087] 34. Triple link

DETAILED DESCRIPTION OF THE INVENTION

[0088] In FIG. 1 a three bladed folding propeller 1 is seen in an operative position, where the hub 2 holds the blades 3 in an unfolded position and extending in a more or less radial direction from the hub 2. The blades 3 are fastened to the hub 2 at the blade roots 8, and at the end of the hub 2 an anode 5 is seen at a hub end cap 6. On the side of the hub 2 a lockbox 7 is seen installed.

[0089] FIG. 2 shows the same three bladed folding propeller 1 as seen in FIG. 1, but here seen in a disassembled state. In this figure the gears 8 at the blade roots 4 are seen, which will secure that all three blades 3 will engage in synchrony. Further the pivot pins 9 are seen in a triangular structure and the holes 10 in the hub 2 for the pivot pins 9 are also seen. At the vertex 11 of the pivot pin triangle a cross dowel 12 is seen having a threaded hole 13 for a locking screw 14. The locking screw 14 will be inserted through a central hole in the lockbox 7 and the cross dowel will be installed in a mating hole 15 at the hub 2.

[0090] The pivot pins 9 will be installed in the holes 10 through the lockbox seat 16 (common aperture). The cross dowels 12 will be installed at the hub 2 and through holes 17 in flanges 18 at the lockboxes 7, which will secure the triangular pivot pin structure and the blade roots 4 in the cut outs 19 in the hub 2 in a very solid manner.

[0091] The anode 5 is installed at the hub end cap 6 using a bolt that engages a threaded hole in said hub end cap. The hub end cap 6 is installed at the hub 2 using bolts that engage threaded holes at the ends of the cross dowels 12. On the lower side of the hub end cap 6 a recess at each hole is arranged, where each recess is suitable for receiving the end of a cross dowel 12. This way the cross dowels 12 are supported by the hub end cap 6 and the hub end cap 6 becomes a part of the structural arrangement and contributes in transferring the loads acting on the folding propeller 1 when in use.

[0092] FIG. 3 shows the same triangular pivot pin structure as seen in FIG. 2 and still in a partly assembled state. The pivot pins 7 are seen having their respective first ends 20 and second ends 21 arranged in a triangular shape, where two pivot pins ends 20, 21 are arranged adjacent each other. The respective ends 20, 21 are shaped with engagement means 22 for engagement with a lockbox 7.

[0093] FIG. 4 shows a cross sectional view of a hub 2, where pivot pins 9 are arranged in holes 10 in the hub 2. Cross dowels 12 are installed at the vertex 11 of the triangle and the lockboxes 7 are held in place in the lockbox seats 16 by locking screws 14. Here it is seen that the lockboxes 7 engage the respective ends 20, 21 of two adjacent pivot pins 9 and thus hold the triangular structure in a fixed position.

[0094] FIG. 5 shows a side view of the hub seen in FIG. 4 and indicates a view line A-A with reference to FIG. 4.

[0095] In FIG. 6 three pivot pins 9 are arranged in a triangle in a second configuration, where the first end 20 and the second end 21 of the pivot pins 9 are designed differently, but where two adjacent ends 20, 21 altogether constitute engagement means 22 having a mating surface 23 for the internal surface 24 of a lockbox 7. The mentioned surfaces 23, 24 may be cylindrical or frustoconical and they may comprise mating threads 26 or they may be smooth surfaces. In this configuration the lockboxes 7 comprise a central hole 25 for a locking screw 14, where the locking screw 14 via a hole 27 in one or two adjacent pivot pin ends 20, 21 is fastened in a threaded hole 13 in a cross dowel 12.

[0096] FIG. 7 shows a cross sectional view of the assembly as described above, where two pivot pins 9, a lockbox 7, a cross dowel 12 and a locking screw 14 is seen.

[0097] FIG. 8 shows three pivot pins 9 arranged in a triangle in a third configuration, more or less as also seen in FIG. 6 and in FIG. 7. The main difference is that the lockboxes 7 are rectangular and with conical/wedge shaped internal surfaces 24 shaped to mate the likewise conical/wedge shaped surface at the respective ends 20, 21 of the pivot pins 9. A locking screw 14 will secure the lockboxes 7 in place when installed.

[0098] FIG. 9 shows a cross sectional view of the configuration seen in FIG. 8, where two pivot pins 9, a lockbox 7, a cross dowel 12 and a locking screw 14 are seen. Further the angle 28 of the conical/wedge shaped surfaces 23, 24 is illustrated.

[0099] In FIG. 10 three pivot pins 9 are arranged in a triangle in a fourth configuration, where the lockboxes 7 comprise an internal surface 24, which surface may or may not comprise threads 26 for engaging mating threads 26 at the surface 23 of the pivot pin 9 ends 20, 21. The lockboxes 8 may or may not comprise threads 26 at the outer surface 29 of the lockbox 7. Said threads 26, if present, are designed to engage a mating thread 26 at the respective surfaces 30 of the lockbox seats. This type of lockbox 7 is designed to be installed by being screwed onto the ends 20, 21 of the pivot pins 9 or into the lockbox seat 16 by a suitable tool e.g. a hex key. In this configuration there are no cross dowels 12, but instead three bolts 31 are arrangedone in each vertex 11 of the pivot pin triangle. The bolts 31 serve as support for the pivot pins 9, but also as fasteners for the hub end cap 6 as seen in FIGS. 1, 2 and 4.

[0100] In FIG. 11 a cross sectional drawing of a hub 2 is seen having pivot pins 9 for a three bladed folding propeller 1 and with side links 32. Side links 32 act as reinforcement and hold the pivot pins 9 in the correct position when forces are acting during rotation of the folding propeller 1. The side links 32 are made from steel or another suitable material and they may be embedded in the hub material or they may be installed as a kind of bearing material between the blade root 4 and the hub 2.

[0101] FIG. 12 shows a side link 32 as mentioned above, where holes 33 for the pivot pins 9 are seen clearly.

[0102] FIG. 13 shows a cross sectional drawing of a hub 2 and pivot pins 9 for a three bladed folding propeller 1, with a triple link 34. The triple link 34 acts as the side link 32 seen in FIGS. 12 and 13, but is connected to all three pivot pins 9. The blade roots 4 will need to have a central dividing slit in order to accommodate the legs of the triple link 34. The side link 32 may also be arranged as a three part triple link in the same manner as seen in FIG. 14 but where three individual side links 32 are arranged centrally at the hub 2.

[0103] FIG. 14 shows a triple link 34 as mentioned above, where holes 33 for the pivot pins 9 are seen clearly.

[0104] The invention is not limited to the embodiments described herein, and may be modified or adapted without departing from the scope of the present invention as described in the patent claims below.