EP0375684A4

EP0375684A4 - Kick-up rudder assembly

Info

Publication number: EP0375684A4
Application number: EP19880904886
Authority: EP
Inventors: Scott S. Albert; Winton P. Mcmillen
Original assignee: Individual
Current assignee: SCAT MARINE PRODUCTS Inc
Priority date: 1987-05-13
Filing date: 1988-05-13
Publication date: 1990-09-26
Also published as: EP0375684A1; WO1988008809A1

Abstract

A kick-up rudder assembly (11), including a rudder (13) and a lattch (51, 53) to hold the rudder (11) in an upright position, wherein the rearward force of water on the rudder causes the latch (51, 53) to more firmly engage. Advantageously, the latch (51, 53) releases in response to sufficient rearward force on the rudder (13) and the minimum upward force on the rudder (13) sufficient to release the latch (51, 53) will be less than the minimum rearward force on the rudder (13) sufficient to release the latch (51, 53). Also advantageously, the amount of force sufficient to release the latch (51, 53) is adjustable. Another aspect of the invention being a kick-up rudder assembly (11), comprising a rudder (13) having a latch (51, 53) to hold the rudder (13) in an upright position, wherein the rudder (13) rotates about a first pivot (51, 53) in response to rearward water pressure, and about a second pivot (33) to release the latch (51, 53), wherein the first pivot advantageously includes the latch (51, 53) itself.

Description

KICK-UP RUDDER ASSEMBLY Background of the Invention This invention relates generally to rudders for boats, and particularly to kick-up rudders. Boat rudders generally comprise a vertical blade rotatable about a vertical axis secured to the stern of a boat to enable the boat to be steered. Typically, the rudder either lies completely under the stern of the boat and is attached to a tiller by a rod extending up through the deck, or extends upward out of the water and is secured to a rudder housing, or directly to the boat's transom.

Sometimes the rudder is adapted to be pivoted upward about a horizontal axis to prevent the rudder from being damaged while beaching, or while maneuvering in shallow water. Unfortunately, these kick-up rudders often require that the rudder be rigidly secured in an upright position to prevent the rudder from rotating upward due to the resistance of water on the rudder when the boat is underway. This is undesirable in that, so secured, the rudder is susceptible to damage due to impact with an unexpected obstruction, and in that it requires the skill and attention of the operator to determine when it is necessary to raise the rudder. Kick-up rudders designed to avoid these drawbacks are typically overly complex or difficult to operate. What is needed is a simple, reliable kick-up rudder assembly which will automatically rotate upward upon forcible impact with the bottom or an obstruction, but will remain securely upright even in rough seas.

Summary of the Invention The invention is a kick-up rudder assembly including a rudder and a latch to hold the rudder in an upright position, wherein the rearward force of water on the rudder causes the latch to engage more firmly. Advantageously, when sufficient rearward force is applied to the rudder, the latch will release. Since the latch engages more firmly in response to water pressure driving the rudder rearward, it is unnecessary to secure the rudder in an upright position. Furthermore, since the latch advantageously releases in response to sufficient rearward force on the rudder, it is unnecessary for the operator to determine when the latch needs to be released or to release the latch.

Desirably, the minimum upward force on the rudder sufficient to release the latch will be less than the minimum rearward force on the rudder sufficient to release the latch. This will have the two-fold effect of causing the latch to release more easily when the rudder strikes bottom when a boat is being beached, and making it easier for the operator lifting the rudder to release the latch and raise the rudder. The amount of force sufficient to release the latch is preferably adjustable.

Another aspect of the invention is a kick-up rudder assembly, comprising a rudder having a latch to hold the rudder in an upright position, wherein the rudder rotates about a first pivot in response to rearward water pressure, and about a second pivot to release the latch.

Advantageously, the first pivot includes the latch itself.

One embodiment of the invention is a kick-up rudder assembly, including a rudder housing and a rudder. The rudder housing is rotatable about a vertical axis, and the rudder is rotatably and translatably mounted on said housing. The assembly is provided with a first cam extending from the leading edge of the rudder, and a second cam extending from the housing. These cams form a latch which substantially limits the rotation of the rudder when the latch is engaged. A dampener biases the latch into engagement, but is sufficiently deformable to permit the latch to be released. Description of the Drawings These and other features of the invention will now be described with reference to drawings of a preferred embodiment which is intended to illustrate, and not to limit, the invention, and in which:

Figure 1 is a sectional view of the kick-up rudder assembly of the present invention;

Figure 2 is a sectional view illustrating the release of the latch mechanism of the assembly of Figure 1, with the further upward rotation of the rudder shown in phantom;

Figure 3 is an exploded partial perspective view illustrating several components of the assembly of Figure 1; Figure 4 is a partial perspective view illustrating an alternative embodiment of a cam extending from the rudder; Figure 5 is an enlarged partial sectional view of an alternative embodiment of the rudder assembly of the present invention; Figure 6 is a partial sectional view of the assembly of Figure 1, illustrating the position of the rudder assembly in response to force at, and in the direction of, the arrow;

Figure 7 is an enlarged partial sectional view of the assembly of Figure 1, illustrating the release of the latch by means of force exerted at, and in the direction of, the arrow;

Figure 8 is an enlarged partial sectional view of the assembly of Figure 1, illustrating the compression of the dampener by the shaft; and

Figure 9 is an enlarged partial sectional view illustrating the cam of Figure 4.

Detailed Description of the Preferred Embodiment Referring to Figures 1 and 3, the kick-up rudder assembly 11 includes a flat, elongate rudder 13 and a yoke-shaped rudder housing 15. The housing 15 includes a pair of generally C-shaped sides 17 joined at the top and bottom by connecting portions, 19 and 21, respectively. The housing 15 is rotatable about a vertical axis A, and is controlled by means of a tiller 23 secured to the housing 15 by a pin 25 or other suitable means.

The rudder 13 has a leading edge 27 and a trailing edge 29 and is provided with a disc-shaped receptacle or cavity 31 at one end. The rudder 13 is secured to the housing 15 by means of a cylindrical shaft 33 which extends through the cavity 31 and is itself secured snugly within bores in the sides 17 of the housing 15 by cotter pins or other suitable means. Desirably, the shaft 33 is easily removable to facilitate the replacement and repair of assembly components. Advantageously, the rudder 13 is provided with an elongate handle 35 extending from the trailing edge 29 of the rudder proximate the cavity 31.

As best seen in Figures 3 and 6, a disc-shaped resilient dampener 37 of heavy closed cell neoprene foam having a coaxial bore 39 slightly larger than the diameter of the shaft 33 fits tightly within the rudder cavity 31. To ensure that the rudder 13 is freely rotatable relative the shaft 33, a rigid, cylindrical tube-shaped lining 41 is provided between the dampener 37 and the shaft 33 to prevent the shaft 33 from sticking to or damaging the foam.

As illustrated in Figures 1-3, the rudder housing 15 may be secured to a deck 43 and a hull 45 of a boat by means of coaxial pintles, 47 and 49, extending from the top and bottom connecting portions, 19 and 21, respectively, of the housing 15. Naturally, it is possible for the housing 15 to be secured to brackets, which are themselves secured to the transom of the boat, or for the housing 15 to be secured by other means. It is desirable that the connecting means permits the 'housing 15 enough freedom of rotation about the vertical axis A to allow the craft to be steered. The rudder is provided with a first cam 51 positioned along and extending from the leading edge 27 of the rudder. As best seen in Figure 1, this first cam 51 cooperates with a second cam 53 to form a latch 55 which prevents the rudder 13 from rotating upward about the shaft 33. When the latch 55 is engaged and no external forces are exerted upon the rudder 13, the dampener 37 holds the shaft 33 in a relaxed position (one minimizing the compression of the dampener) in the middle of the cavity/dampener, thereby maintaining the rudder 13 in a generally upright position. As will be discussed in reference to an alternative embodiment, the dampener may also bias the rudder downward when the rudder is in an upright position. It would naturally be possible to utilize a dampener 37 having an internal bore significantly larger than the shaft 33 or having an outer configuration which would permit the movement of the dampener relative the sides of the cavity 31. This, however, would provide a certain amount of free play in the rudder 13.

As shown in Figure 6, when force is exerted on the portion of the rudder 13 below the cam 51, the second cam 53 forms a fulcrum about which the rudder 13 rotates. This causes the rudder 13 to move relative the shaft 33, thereby compressing the dampener 37. As illustrated in Figure 8, this compressions occurs not only along the path of movement of the rudder 13, but also over a relatively large area both above and below the path of movement. The greater the movement of the rudder 13 relative the shaft 33, the greater the compression, and the greater the resistance of the dampener 37 to movement of the rudder 13, not only along the initial path of movement, but also to movement which would release the latch 55.

The shape of the cavity 33 also inhibits the release of the latch 55. As illustrated in Figures 6 and 8, the farther the lower portion of the rudder 13 is driven rearward, the less the rudder can move upward without encountering the rigid walls of the cavity 31. When the rearward force, illustrated by the arrow on Figure 6, on the rudder is great enough, the upper portion of the rudder is driven so far forward against the shaft 33 that the walls of the cavity 31 will not permit sufficient upward movement of the rudder 13 to permit the latch 55 to be released. In this situation, sufficient force must be applied to the rudder to drive the rudder upward against the shaft to cause the upper portion of the rudder to slide rearward due to the force of the shaft against the wall of the cavity to permit enough vertical movement by the rudder to release the latch.

Thus, when a directly rearward force is applied to the lower portion of the rudder 13, both the dampener 37 and the cavity 31 configuration inhibit the upward movement of the rudder relative the shaft 33, thereby preventing the rudder from rotating upward unless sufficient force is applied. In practice, it has been found that it is desirable to adjust the assembly so that a horizontal force of 45 lbs. on the end of the rudder is required to release the latch 55.

In contrast to the relatively large amount of force required to release the latch 55 by exerting force on the lower leading edge of the rudder 13, it is a relatively simple matter to release the latch and rotate the rudder upward by means of the rudder's handle 35. As illustrated in Figure 7, the reason for this is two-fold. First, instead of the major force component driving the rear wall of the cavity 31 against the shaft 33 and compressing the dampener 37 before significant upward movement of the rudder occurs, the major component of the force applied to the handle moves the rudder upward from its relaxed position, with the shaft in the middle of the cavity 31, largely minimizing the resistance of the dampener to the movement of the rudder. Second, instead of being driven forward by the major force component, where the shaft limits the upward movement of the rudder due to the rigid walls of the cavity, the major component of force applied to the handle drives the rudder upward, causing the latch to be released before the shaft significantly limits the rudder's upward movement.

For similar reasons, significantly less force needs to be applied to the lower portion of the rudder to release the latch 55 when the force has a significant upward component such as would be exerted when the rudder 13 strikes bottom when a boat is being beached. The greater the vertical force component exerted, the less the dampener 37 will be compressed before the latch 55 is released, and the less the shaft 33 will limit the upward movement of the rudder 13, due to the rigid walls of the cavity 31.

Although the cam 51 extending from the leading edge 27 of the rudder may be integrally formed with the rudder 13, the cam may also be a separate element. As shown in Figures 4 and 9, this separate cam 51 may advantageously be provided with a vertical internal slot 57 for receiving a screw 59 or other suitable fastener to permit the cam 51 to be raised or lowered to "fine-tune" the latch 55. By increasing the distance between the cam 51 and the cavity 31, it is possible to adjust the latch 55 to compress the dampener 37 when the latch is engaged and the rudder 13 is in an upright position. Alternatively, it is possible to decrease the overlap between the first cam 51 and second cam 53 so that the amount by which the dampener 37 must be deformed to release the latch 55 and permit the rudder 13 to be rotated upward is decreased.

Referring to Figure 5, an alternative embodiment of the assembly 11 is advantageously provided with means for rotating the rudder 13 downward to engage the latch 55. As illustrated, this means may take the form of a cord 61 attached near the cavity 31 along the leading edge 27 of the rudder 13 and threaded through the tiller 23 over the pin 25. The cord can either extend out of the tiller far enough to prevent it from sliding entirely into the tiller when the rudder 13 is rotated upward, or can be tied to a piece of elastic and provided with a balled end so the excess cord will be gathered within the tiller when the rudder is in an upright position. By pulling on the end of the cord 61, the operator can rotate the rudder to an upright position so the latch 55 engages. As with the elongate handle, the major component of force applied to the cord 61 moves the rudder upward from its relaxed position, rather than driving the rear wall of the cavity 31 against the shaft 33 and compressing the dampener before significant upward movement of the rudder occurs. Likewise, since the major force component applied to the cord moves the rudder upward, the latch 55 will engage before the shaft 33 significantly limits the rudder's upward movement.

As illustrated in Figure 5, the rudder housing 15 may be provided with a retractable pintle 63 to permit the assembly 11 to be rapidly mounted and dismounted. In operation, the assembly 11 can be mounted by positioning the lower pintle 49 in a hole in the hull 45 of the craft, pulling the pintle 63 downward by means of a connecting rod 65 so that the outward bias of a spring 67 enclosed in the housing 15 is overcome, aligning the pintle 63 with a hole in the craft's deck 43, and releasing the rod 65 so the spring 67 will force the pintle 63 outward so that it is received by the hole in the deck 43. As shown in Figure 2, once the assembly 11 is mounted, the handle 35 can be lifted to rtelease the latch 55 in order to raise the rudder 13 when the boat is being launched. When the boat enters deeper water, the cord 61, shown in Figure 5, can be pulled to rotate the rudder 13 downward to engage the latch. As shown in Figure 6, the latch will securely hold the rudder 13 upright while the boat is underway despite the pressure of water against the lower portion of the rudder. However, should the rudder forcefully strike an unexpected obstruction, the latch 55 is designed to release and allow the rudder to rotate upward rather than be damaged. Finally, when the boat is being beached, the handle 35 can again be used to release the latch 55 and rotate the rudder upward, or the rudder can be left upright until it strikes the bottom with sufficient force to release the latch, thereby permitting the rudder to rotate freely upward.

Claims

WE CLAIM:

1. A kick-up rudder assembly, comprising: an elongate rudder having a first and a second end; a latch engageable with said rudder between said ends to hold said rudder in an upright position; and a mounting device cooperating with said first end of said rudder allowing said ^"rudder to rotate but engaging said latch more firmly in response to water pressure driving said second end of said rudder rearward.

2. The^' assembly of Claim 1, wherein sufficient rearward force on said rudder will cause said latch to release. 3. The assembly of Claim 1, wherein the minimum upward force on said rudder sufficient to release said latch is less than the minimum rearward force on said rudder sufficient to release said latch.

4. The assembly of Claim 3, wherein the force sufficient to release said latch can be adjusted.

5. A kick-up rudder assembly, comprising a rudder and a latch to hold said rudder in an upright position, wherein said rudder rotates about a first pivot in response to rearward water pressure, and rotates about a second pivot to release said latch.

6. The assembly of Claim 5, wherein said first pivot comprises said latch.

7. A kick-up rudder assembly, comprising: a rudder housing rotatable about a vertical axis; a rudder having a leading edge, said rudder rotatably and translatably mounted on said housing; a first cam extending from said leading edge of said rudder; a second cam extending from said housing, said first cam and said second cam forming a latch to substantially limit the rotation of said rudder when said latch is engaged; and a dampener biasing said rudder to translate downward relative said housing, said dampener 5 sufficiently deformable to permit translation of said rudder relative said housing to release said latch. 8. The rudder assembly of Claim 7, wherein said dampener biases said rudder to translate backward relative said housing. 0 9. The rudder assembly of Claim 7, additionally comprising a rigid dampener receptacle to limit the movement of said rudder relative said shaft.

10. The rudder assembly of Claim 9, wherein said second cam forms a fulcrum about which said rudder rotates in response to the exertion of force on said rudder below said first cam, and wherein the resistance of said dampener to the movement of said rudder relative said shaft increases with the distance said rudder is displaced from a relaxed position. o 1* The assembly of Claim 10, wherein the amount said receptacle limits the upward movement of said rudder from a relaxed position increases with the distance the lower portion of said rudder is displaced rearward from a relaxed position. 5 12. The assembly of Claim 11, additionally comprising means for rotating said first cam toward said second cam to close said latch and to rotate said rudder downward.

13. The assembly of Claim 11, additionally comprising a retractable pintle coaxial with said vertical axis to mount said assembly to a vessel.

14. The assembly of Claim 11, wherein the position of said first cam relative said leading edge of said rudder is adjustable.

15. The assembly of Claim 11, additionally comprising 5 means for rotating said first cam away from said second cam to release said latch and to rotate said rudder upward.

16. The assembly of Claim 15, wherein said rotation means comprises an elongate handle extending from said trailing edge of said rudder.

17. The assembly of Claim 16, additionally comprising means for rotating said first cam toward said second cam to engage said latch and to rotate said rudder downward.

18. The assembly of Claim 17, additionally comprising a tiller.

19. A rudder assembly comprising: an ^* elongate rudder having a first end and a second end; a cam between said first and said second end engageable with a mating cam to form a latch; and a cavity defined by said first end cooperating with a dampener and allowing said rudder to rotate and translate relative said latch in response to pressure on said second end.