US3572279A - Shock-and-dig-relieving daggerboard - Google Patents

Abstract

DAGGERBOARD SO SHAPED, MOUNTED WITHIN AND CORRELATED WITH THE BOAT WELL, THAT THE BOARD IN RESPONSE TO IMPINGEMENT OF ITS LOWER END WITH THE BOTTOM SUBMERGED BENEATH THE WATER, OR WITH A SOLID FIXED OBJECT, AUTOMATICALLY PIVOTS ABOUT A TRANSVERSE AXIS FIXED WITH THE WELL, TO THEREBY DECREASE THE NORMAL MAXIMUM PRO-

JECTION OF THE BOARD. YIELDING MEANS CONTINUOUSLY URGES THE BOARD INTO NORMAL OPERATING POSITION. THE BOARD MAY ALSO BE MANUALLY ELEVATED OUT OF THE WELL FOR ALL POSITIONS OF PIVOTING THEREOF ABOUT THE AFORESAID AXIS.

Description

Much 23, 1-971 E. c. SMOOT, JR SHOCK-AND-DIG-RELIEVING DAGGERBQARD Filed March 11, 1969 IN vazv roR J (seal) United States Patent 3,572,279 SHOCK-AND-DllG-RELIEVING DAGGERBOARD Ernest Clyde Smoot, Jr., 6218 Dustin Drive, Richmond, Va. 23226 Filed Mar. 11, 1969, Ser. No. 806,081 Int. Cl. B6311 41/00 US. Cl. 114-132 8 Claims ABSTRACT OF THE DISCLOSURE Daggerboard so shaped, mounted within and correlated with the boat well, that the board in response to impingement of its lower end with the bottom submerged beneath the water, or with a solid fixed object, automatically pivots about a transverse axis fixed With the well, to thereby decrease the normal maximum projection of the board. Yielding means continuously urges the board into normal operating position. The board may also be manually elevated out of the well for all positions of pivoting thereof about the aforesaid axis.

This invention relates to improvements in a sailboat keel commonly known as a daggerboard which is specifically a keel board without a pivot pin and which passes through the sailboat by means of a box, trunk or well built in the boat. This is to differentiate from the usual centerboard with pivot pin.

This invention relates more specifically to improvements in the type of keel commonly known as a dagger board, by way of cutting away a certain portion of the daggerboard within the Well, cutting a certain bevel on the lower end of the board, and adding a Spring mechanism and handle to the top of the daggerboard as specified. This improvement permits the daggerboard to pivot about an imaginary pivot at the rear of the daggerboard well. Daggerboards have not before this invention been considered to pivot. This invention has no pivot pin as is a common factor in a centerboard. This invention is an improvement in the art of daggerboard mechanisms, as it can be fitted to any existing or new rectangular daggerboard well in existing or new boats.

The objective of this invention is to provide a pivoting daggerboard and mechanism which can be slipped downward into any daggerboard well using the rectangular width and length as specified by any sailboat design to provide sufficient lateral water resistance for the boat, the board to fit into a well with parallel fore and aft ends, which is the common design in the art, this board so fitted is to allow the bottom-most part of the board to move toward the rear of the boat with the tip end rising slightly from its down position, all of this when striking an object or bottom of waterway, and from this pivoted-back position to allow daggerboard to be pulled up through the well without returning the board to the original draft extreme.

A further objective is to relieve the Suddenness with which the sailboat would stop when striking an object with the board and thus causing the boat occupants to fall or be pitched forward were it not for this shape of the daggerboard with spring mechanism.

A further objective is to prevent the board from digging as tightly as a full draft board upon striking soft bottoms.

Other objectives and advantages of the invention will be apparent from the following description and from the drawing forming a part thereof.

The drawing shows a preferred embodiment of the invention and such embodiment will be described, but it will be understood that various changes may be made from the construction disclosed, and that the drawing ice and description are not to be construed as defining or limiting the scope of the invention, the claims forming a part of this specification being relied upon for that purpose.

Turning now to the drawing, this invention can be represented by one figure With dotted lines showing moved position.

The reference numeral 1 is a daggerboard which is a sheet of plywood, processed wood, plastic or metal. 2 is the open-bottom edge of a conventional rectangular daggerboard well of any sailboat. 3 and 4 respectively are the fore and aft ends of any conventional daggerboard well. 5 is the open-top edge of any daggerboard Well. The dimensions of 2, 3, 4 and 5 can be varied indefinitely provided 3 approximately equals 4 and 2 approximately equals 5 in every configuration. The edge 6 shows that the elevational shape of daggerboard 1 has been cut away along a line drawn from point 7 to point 8. Point 8 is located on the original front edge 9 of the rectangular panel from which daggerboard 1 is sawn out. Point 8 is where front edge 9 of panel intersects the open bottom edge 2 of the well. Point 7 is a point .15 of the length of the top edge 10 ofthe original rectangular panel measuring along 10 from point 14, where 10 and rear edge 11 intersect.

The bottom end 12 of daggerboard 1 is sawn on a slope determined by placing a construction angle with its angle lying atop the original rectangular panel, shown by lines 9, 10, 11 and 13, and then moving this construction triangle so that triangular side 16 passes through the point or corner 14 and triangular side 17 passes through corner 15 of the original rectangular panel. Now that bottom end 12 of the daggerboard has been established as a straight line, round line 11 to line 12 to front edge 18 of completed daggerboard 1 and also round line 18 to line 6. Use full-round or large curves.

19 is a ball-type knob firmly affixed on shank 20. Shank 20 is threaded down into top of daggerboard 1. Plate set 21 consists of two wood or metal plates, one for each side of daggerboard 1, which are fastened to or through the daggerboard to thicken the position where plate set 21 is mounted sufliciently to prevent daggerboard 1 from having the top end slip below well top 5. Lower edge of plate 21 must be rounded as shown to permit movement of the board to its second position. This shape is necessary to permit the unique motion of the board. 22 is a ring or a strap placed around shank 20. Spring 23 has one end hooked in ring 22 and the other end into ring 24 held by metal strap 25. Spring 23 is a coil spring which resists any pull so as to extend its length.

In operation, when the bottom end 12 of daggerboard 1 strikes the bottom of waterway 26, or in the event a submerged object strikes daggerboard edge 18, the board will pivot about point 27 of its well, taking the dottedline position as shown. Suddenness of movement is absorbed by spring 23.

As it is assumed that the bottom of waterway 26 is struck because of a rise in the bottom, a second imaginary and operating bottom 28 of waterway is shown tangent to moved position of daggerboard 1. The height of operating bottom 28 above original bottom 26 will vary with every daggerboard well depth and width.

The purpose of angle edge 6, sawn exactly as hereinbefore expressed, and of bottom end 12, sawn exactly as hereinbefore expressed, is to allow the operator of the boat to pull daggerboard 1, using handle 19, upward through the well passing upwards between well ends 3 and 4 without returning bottom end 12 of daggerboard to the original bottom of waterway 26. The entire daggerboard 1 will move forward and upward from its second position so that its bottom end 12 will not pass below the operating bottom of waterway 28, thus lessening the dig-in of the edge 12 as the boat operator Works the board up to free himself from the soil bottom of the waterway. The entire daggerboard 1 can be pulled out of top of the well if desired by unhooking spring 23 at either end.

It should be understood that the herein shown and described form of daggerboard and mechanism is intended to exemplify the principles of the present invention and that various modifications and rearrangements of its component parts may be made within the scope of the appended claims, wherein I claim:

1. A daggerboard comprising an essentially rigid planar sheet of material having an essentially straight aft edge and a lower forward edge portion parallel with and spaced a fixed distance from said aft edge, said lower forward edge portion extending from the bottom edge of the board, to a first point between the top and bottom of the board, said forward edge continuing upwardly and rearwardly from said first point, in a second straight upper portion, to substantial intersection with the upper terminal of said aft edge, at a second point, and a pair of rigid pivot plates fixed to and projecting laterally from respectively opposite surfaces of said board, contiguous to said second point, said plates having downwardly convex arcuate lower edges in transverse registration, each with the other.

2. The daggerboard of claim 1, said bottom edge extending forwardly and upwardly at an obtuse angle from and with respect to said straight aft edge, the junctions between said aft, bottom, and lower forward edge portion, being faired curves.

3. The daggerboard of claim 2, said obtuse angle being such that said bottom edge makes a right angle With a line through said second point and the extended intersection of said bottom edge with said lower forward edge portion.

4. The daggerboard of claim 1, in combination, a boat having a well rectangular in horizontal section, of a transverse width to receive said daggerboard with a smooth sliding fit, said well having spaced forward and aft vertical surfaces intersecting the bottom of the boat, and upper laterally-spaced parallel fore-and-aft supporting surfaces on opposite sides thereof, said pivot plates resting on said supporting surfaces, respectively, to support said daggerboard within said well.

5. The combination of claim 4, said daggerboard normally having the upper portion of its said aft edge in contact with the aft vertical surface of the well, and pivoting about the transverse line of intersection of said aft vertical surface and the boat bottom, by and in response to impingement of the lower projecting portion of the daggerboard with a fixed object, said plates riding on said fore-and-aft supporting surfaces during pivoting of the board as aforesaid.

6. The combination of claim 5, and means connected between said boat and daggerboard yieldingly urging the aft edge of the latter into contact with said aft vertical surface.

7. The combination of claim 6, said last-named means comprising a spring having one end attached to said daggerboard, adjacent to said second point thereof, and its other end attached to said boat.

8. The combination of claim 5, pivoting of said daggerboard as aforesaid being limited by engagement between the second portion of its forward edge and the forward vertical surface of the well.

References Cited UNITED STATES PATENTS TRYGVE M. BLIX, Primary Examiner

Images